[Federal Register Volume 76, Number 154 (Wednesday, August 10, 2011)]
[Rules and Regulations]
[Pages 49542-49567]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-19812]
[[Page 49541]]
Vol. 76
Wednesday,
No. 154
August 10, 2011
Part II
Department of the Interior
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Fish & Wildlife Services
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Emergency Listing of the
Miami Blue Butterfly as Endangered, and Emergency Listing of the
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly;
Final Rule
Federal Register / Vol. 76 , No. 154 / Wednesday, August 10, 2011 /
Rules and Regulations
[[Page 49542]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2011-0043 MO 92210-0-0008
RIN 1018-AX83
Endangered and Threatened Wildlife and Plants; Emergency Listing
of the Miami Blue Butterfly as Endangered, and Emergency Listing of the
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Emergency rule.
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SUMMARY: We, the Fish and Wildlife Service (Service), exercise our
authority pursuant to section 4(b)(7) of the Endangered Species Act of
1973, as amended (Act), to emergency list the Miami blue butterfly
(Cyclargus thomasi bethunebakeri) as endangered. This subspecies is
currently known to occur at only a few small remote islands within the
Florida Keys. Current population numbers are not known, but are
estimated in the hundreds of butterflies. We are also emergency listing
the cassius blue butterfly (Leptotes cassius theonus), ceraunus blue
butterfly (Hemiargus ceraunus antibubastus), and nickerbean blue
butterfly (Cyclargus ammon) as threatened due to similarity of
appearance to the Miami blue, with a special rule pursuant to section
4(d) of the Act.
Due to the subspecies' severe reduction in geographic range, small
population sizes, and imminent threats, we need to make protective
measures afforded by the Act available to the Miami blue immediately.
This emergency rule provides Federal protection pursuant to the Act for
a period of 240 days. A proposed rule to list the Miami blue butterfly
as endangered and to list the cassius blue butterfly, ceraunus blue
butterfly, and nickerbean blue butterfly as threatened due to
similarity of appearance to the Miami blue is published concurrently
with this emergency rule, and it can be found in this issue of the
Federal Register in the Proposed Rules section.
DATES: This emergency rule becomes effective on August 10, 2011, and
expires April 6, 2012.
ADDRESSES: The supporting information used in this emergency rulemaking
is available for inspection, by appointment, during normal business
hours at the U.S. Fish and Wildlife Service, South Florida Ecological
Services Office, 1339 20th Street, Vero Beach, Florida 32960-3559.
FOR FURTHER INFORMATION CONTACT: Paula Halupa, Fish and Wildlife
Biologist, U.S. Fish and Wildlife Service, South Florida Ecological
Services Office, 1339 20th Street, Vero Beach, Florida 32960-3559 by
telephone 772-562-3909, ext. 257 or by electronic mail:
miamiblueinfo@fws.gov.
SUPPLEMENTARY INFORMATION:
Background
The Miami blue is a small, brightly colored butterfly approximately
0.8 to 1.1 inches (1.9 to 2.9 centimeters [cm]) in length (Pyle 1981,
p. 488) with a forewing length of 0.3 to 0.5 inches (8.0 to 12.5
millimeters) (Minno and Emmel 1993, p. 134). Wings of males are blue
above (dorsally), with a narrow black outer border and white fringes;
females are bright blue dorsally, with black borders and an orange/red
and black eyespot near the anal angle of the hindwing (Comstock and
Huntington 1943, p. 98; Minno and Emmel 1993, p. 134). The underside is
grayish with darker markings outlined with white and bands of white
wedges near the outer margin. The ventral hindwing has two pairs of
eyespots, one of which is capped with red; basal and costal spots on
the hindwing are black and conspicuous (Minno and Emmel 1993, p. 134).
The winter (dry season) form is much lighter blue than the summer (wet
season) form and has narrow black borders (Opler and Krizek 1984, p.
112). Seasonal wing pattern variation may be caused by changes in
humidity, temperature, or length of day (Pyle 1981, p. 489). Miami blue
larvae are bright green with a black head capsule, and pupae vary in
color from black to brown (Minno and Emmel 1993, pp. 134-135).
The Miami blue is similar in appearance to three other sympatric
(occupying the same or overlapping geographic areas without
interbreeding) butterflies that occur roughly in the same habitats:
cassius blue (Leptotes cassius theonus), ceraunus blue (Hemiargus
ceraunus antibubastus), and nickerbean blue (Cyclargus ammon). The
Miami blue is slightly larger than the ceraunus blue (Minno and Emmel
1993, p. 134), but the ceraunus blue has a different ventral pattern
and flies close to the ground in open areas (Minno and Emmel 1994, p.
647). The cassius blue often occurs with the Miami blue, but has dark
bars rather than spots on the undersides of the wings (Minno and Emmel
1994, p. 647). The Miami blue can be distinguished from the ceraunus
blue and cassius blue by its very broad white ventral submarginal band,
the dorsal turquoise color of both sexes, and the orange-capped
marginal eyespot on the hind wings (Opler and Krizek 1984, p. 112). The
nickerbean blue is also similar to the Miami blue in general appearance
but is considerably smaller; it has three black spots across the basal
hindwing, while the Miami blue has four (Calhoun et al. 2002, p. 15).
The larvae and pupae of the nickerbean blue closely resemble the Miami
blue (Calhoun et al. 2002, p. 15).
In a comparison of Miami blue butterfly specimens within the
Florida Museum of Natural History (FLMNH) collection, Saarinen (2009,
pp. 42-43) found a significant difference in wing chord length between
males and females, with males having shorter wing chords than females.
However, no significant differences were found between wing chord
length in comparing wet and dry seasons, decade of collection, seven
different regions, or between eastern mainland and Keys specimens
(Saarinen 2009, pp. 42-43). No seasonal size differences were found
between the mainland populations and those in the Keys (Saarinen 2009,
p. 43).
In a comparison of body size in a recent Miami blue population
(BHSP 2002-2006), females were significantly larger than males, and
individuals sampled in the wet season were also significantly larger
than in the dry season (Saarinen 2009, p. 43). In a comparison of
recent Bahia Honda State Park (BHSP) individuals with specimens from
historical collections (FLMNH data), BHSP individuals were
significantly larger than historical specimens, females from BHSP were
also significantly larger than historical female specimens, and BHSP
adults measured in wet seasons were larger than those sampled in wet
seasons in museum collections (Saarinen 2009, p. 43). Saarinen (2009,
p. 47) suggested that perhaps larger adults were selected for over time
with larger adults being more capable of dispersing and finding food
and mates. Limited food resources during larval development or abrupt
termination of availability of food in the last larval instar can lead
to early pupation and a smaller adult size (T.C. Emmel, pers. comm., as
cited in Saarinen 2009, p. 47). It is possible that differences in host
plant (e.g., nutrition) and age of specimens (e.g., freshness) may also
be factors when comparing body size between recent specimens and those
from historical collections.
[[Page 49543]]
Taxonomy
The Miami blue belongs to the family Lycaenidae (Leach), subfamily
Polyommatinae (Swainson). The species Hemiargus thomasi was originally
described by Clench (1941, pp. 407-408), and the subspecies Hemiargus
thomasi bethunebakeri was first described by Comstock and Huntington
(1943, p. 97). Although some authors continue to use Hemiargus, Nabokov
(1945, p. 14) instituted Cyclargus for some species, which has been
supported by more recent research (Johnson and Balint 1995, pp. 1-3, 8-
11, 13; Calhoun et al. 2002, p. 13; K. Johnson, Florida State
Collection of Arthropods, in litt. 2002). There are differences in the
internal genitalic structures of the genera Hemiargus and Cyclargus
(Johnson and Balint 1995, pp. 2-3, 11; K. Johnson, in litt. 2002). Kurt
Johnson (in litt. 2002), who has published most of the existing
literature since 1950 on the blue butterflies of the tribe
Polyommatini, reaffirmed that thomasi belongs in the genus Cyclargus
(Nabokov 1945, p. 14), not Hemiargus. Accordingly, Cyclargus thomasi
bethunebakeri (Pelham 2008, p. 256) and its taxonomic standing is
accepted (Integrated Taxonomic Information System 2011, p. 1).
In 2003, questions about the taxonomic identity of Miami blues from
BHSP were raised by a few individuals. To address these questions, the
Service sent two pairs (male and female) of adult specimens to three
independent taxonomists/reviewers (Dr. Jacqueline Miller, Associate
Curator, Allyn Museum of Entomology (AME), FLMNH; Dr. Paul Opler,
Colorado State University; and John Calhoun, Museum of Entomology,
Florida State Collection of Arthropods) for verification. To avoid harm
to the wild population, scientists examined moribund adults from a
captive colony generated from individuals taken from BHSP. Each
reviewer independently confirmed through various means (e.g.,
comparison with confirmed specimens, dissection and examination of
genitalia) that the identities of the adult specimens examined were
Cyclargus thomasi bethunebakeri (J. Miller, in litt. 2003; P. Opler, in
litt. 2003; J. Calhoun, in litt. 2003a). We received an additional
confirmation from Lee Miller, Curator (AME, FLMNH) stating that the
identities of the adult specimens examined were Cyclargus thomasi
bethunebakeri (L. Miller, in litt. 2003). Taxonomic verification by
genitalic dissection of the Miami blue at Key West National Wildlife
Refuge (KWNWR) has not occurred, but preliminary molecular evidence has
confirmed that they are the same taxon (E.V. Saarinen, unpub. data, as
cited in Saarinen 2009, p. 18).
Life History
Like all butterflies, the Miami blue undergoes complete
metamorphosis, with four life stages (egg, caterpillar or larva, pupa
or chrysalis, and adult). The generation time is approximately 30-40
days (Carroll and Loye 2006, p. 19; Saarinen 2009, p. 22, 76). Although
a single Miami blue female can lay 300 eggs, high mortality may occur
in the immature larval stages prior to adulthood (T. Emmel, University
of Florida [UF], pers. comm. 2002). Reported host plants are blackbead
(Pithecellobium spp.), nickerbean (Caesalpinia spp.), balloonvine
(Cardiospermum spp.), and presumably Acacia spp. (Kimball 1965, p. 49;
Lenczewski 1980, p. 47; Pyle 1981, p. 489; Opler and Krizek 1984, p.
113; Minno and Emmel 1993, p. 134; Calhoun et al. 2002, p. 18; Cannon
et al. 2010, p. 851). In addition, Rutkowski (1971, p. 137) observed a
female laying one egg just above the lateral bud on snowberry
(Chiococca alba). Eggs are laid singly near the base of young pods or
just above the lateral buds of balloonvine and the flowers of
leguminous trees (Opler and Krizek 1984, p. 113; Minno and Emmel 1993,
p. 134); flower buds and young tender leaves of legumes are preferred
(Minno and Minno 2009, p. 78; M. Minno, pers. comm. 2010).
On nickerbean (Caesalpinia spp.), females lay eggs on developing
shoots, foliage, and flower buds (Saarinen 2009, p. 22). Oviposition
occurs throughout the day with females often seeking terminal growth
close to the ground (< 3.3 feet [< 1 meter]) or in locations sheltered
from the wind (Emmel and Daniels 2004, p. 13). Eggs are generally laid
singly, but may be clustered on developing leaves, shoot tips, and
flower buds (Saarinen 2009, p. 22). After several days of development,
larvae chew out of eggs and develop through four instar stages, with
total larval development time lasting 3 to 4 weeks, depending upon
temperature and humidity (Saarinen 2009, p. 22). Fourth instar larvae
pupate in sheltered or inconspicuous areas, often underneath leaf
whorls or bracts (Saarinen 2009, p. 22). Adult butterflies eclose
(emerge) after 5 to 8 days, depending on temperature and humidity
(Saarinen 2009, p. 22).
On blackbead plants, females lay eggs on flower buds and emerging
leaves (Cannon et al. 2010, p. 851). Oviposition on, or larval
consumption of, mature blackbead leaves was not observed (Cannon et al.
2010, p. 851). Thus, Cannon et al. (2010, p. 851) suggest that
abundance may be limited by the availability of young blackbead leaves
and buds for egg-laying, even if abundant suitable nectar sources (see
Habitat) are available year-round.
On balloonvine, females lay single eggs near fruit (capsules)
(Carroll and Loye 2006, p. 18). Newly hatched larvae chew distinctive
holes through the outer walls of the capsules to access seeds (Minno
and Emmel 1993, p. 134). After consuming seeds within the natal
capsule, larvae must crawl to a sequence of two or three balloons
before growing large enough to pupate. Attending ants follow through
the same holes (see Interspecific relationships below). Miami blues
were also observed to commonly pupate within mature capsules (sometimes
with ants in attendance within the capsule) (Carroll and Loye 2006, p.
20).
The Miami blue has been described as having multiple, overlapping
broods year-round (Pyle 1981, p. 489). Adults can be found every month
of the year (Opler and Krizek 1984, pp. 112-113; Minno and Emmel 1993,
p. 135; 1994, p. 647; Emmel and Daniels 2004, p. 9; Saarinen 2009, p.
22). Opler and Krizek (1984, pp. 112-113) indicated one long winter
generation from December to April, during which time the adults are
probably in reproductive diapause (a period in which growth,
development, and physiological activity is suspended or diminished); a
succession of shorter generations was thought to occur from May through
November, the exact number of which is unknown. Glassberg et al. (2000,
p. 79) described the Miami blue as having occurred all year, with three
or more broods. Researchers have noted a marked decrease of adults from
December to early February at BHSP, indicative of a short diapause
(Emmel and Daniels 2003, p. 3; 2004, p. 9). Saarinen also noted that
the life cycle at BHSP slowed in winter months and suspected a slight
diapause (E.V. Saarinen and J.C. Daniels, unpub. data, as cited in
Saarinen 2009, p. 22). Conversely, Minno (pers. comm. 2010) notes that
there have been records of adults in December and January and suggests
that this tropical butterfly may not have a winter diapause, but
rather, emergence may be delayed by cold temperatures in some years.
Salvato and Salvato (2007, p. 163) and Cannon et al. (2010, pp. 849-
850) also reported numerous adults at BHSP and KWNWR, respectively,
during winter months.
Information on adult lifespan is limited. Adults may live a maximum
of 9 days, but most adults live only a few
[[Page 49544]]
days (J. Daniels, UF, pers. comm. 2003a, 2003b). In general, adult
butterflies survive less than a week in the wild; there are
approximately 8-10 generations per year (Saarinen et al. 2009a, p. 31).
Generations are not completely discrete due to the variance in
development time of all life stages (Saarinen et al. 2009a, p. 31).
Range size and dispersal--Adult Miami blues are nonmigratory and
appear to be very sedentary (Emmel and Daniels 2004, p. 6). Based on
mark-recapture work conducted in 2002-2003, recaptured adults (N=39)
moved an average of 6.53 +/- 11.68 feet (2.0 +[sol]- 3.6 meters), four
individuals moved between 25 and 50 feet (7.6 and 15.2 meters), and
only three individuals moved more than 50 feet (15.2 meters) over a few
days (Emmel and Daniels 2004, pp. 6, 32-38). Few individuals were found
to move between the lower and upper walkway locations of the south end
colony sites at BHSP (approximately 100 feet [30.5 meters]); no
movement between any of the smaller individual, isolated colony sites
was recorded (Emmel and Daniels 2004, p. 6). However, Saarinen (2009,
pp. 73, 78-79) found that genetic exchange between colonies occurred at
BHSP and noted that small habitat patches may be crucial in providing
links between subpopulations in an area.
Interspecific relationships--As in many lycaenids worldwide (Pierce
et al. 2002, p. 734), Miami blue larvae associate with ants (Emmel
1991, p. 13; Minno and Emmel 1993, p. 135; Carroll and Loye 2006, pp.
19-20) in at least four genera of ants in three subfamilies of
Formicidae (Saarinen and Daniels 2006, p. 71; Saarinen 2009, p. 131,
133). Miami blues using nickerbean at BHSP and Everglades National Park
(ENP) (reintroduced individuals) were variously tended by Camponotus
floridanus, C. planatus, Crematogaster ashmeadi, Forelius pruinosus,
and Tapinoma melanocephalum (Saarinen and Daniels 2006, p. 71; Saarinen
2009, pp. 131, 138). C. floridanus was the primary ant symbiont,
commonly found tending larvae; other ant species were encountered less
often (Saarinen and Daniels 2006, p. 70; Saarinen 2009, pp. 131-132).
Liquid (honeydew) exuded from the butterfly's dorsal nectary organ
(honey gland) was actively imbibed by all species of ants (Saarinen and
Daniels 2006, p. 70; Saarinen 2009, p. 132).
Late Miami blue instars were always found in association with ants,
but early instars, prepupae, and pupae were frequently found without
ants present (Saarinen and Daniels 2006, p. 70). Forelius pruinosus and
Tapinoma melanocephalum were observed to derive honeydew from Miami
blues they tended, but were not observed to actively protect them from
any predator (Saarinen and Daniels 2006, p. 71; Saarinen 2009, p. 133).
However, the presence of ants in the vicinity of larvae may potentially
deter predators (Saarinen and Daniels 2006, pp. 71, 73; Saarinen 2009,
p. 133, Trager and Daniels 2009, p. 480). Two additional ants,
Paratrechina longicornis and P. bourbonica, have been identified as
potential associates of the Miami blue (Saarinen and Daniels 2006, pp.
70-71; Saarinen 2009, pp. 131, 138). P. longicornis was found near
Miami blue larvae and appeared to tend them during brief encounters; P.
bourbonica tended another lycaenid, martial scrub-hairstreak (Strymon
martialis) at BHSP (Saarinen and Daniels 2006, p. 70). Cannon et al.
(2007, p. 16) also observed two ant species attending Miami blues on
KWNWR. Based on photographs, the ants appeared to be C. inaequalis and
P. longicornis. C. planatus was observed on blackbead.
In the 1980s, Miami blue larvae that fed on balloonvine in the
upper Keys were also tended by ants (C. floridanus and C. planatus)
(Carroll and Loye 2006, pp. 19-20). Carroll and Loye (2006, p. 20)
found that Camponotus spp. raised with Miami blue larvae lived longer
than ants raised with larvae of other lycaenid species or without any
food source, demonstrating that larval secretions benefit ants.
More recently, Trager and Daniels (2009, p. 479) most commonly
found C. floridanus and C. planatus associated with wild and recently
released Miami blue larvae. In a comparison of Miami blue larvae raised
with and without ants, no effect of ant presence was found on any
measurements of larval performance (e.g., age at pupation, pupal mass,
length of pupation, total time as an immature) (Trager and Daniels
2009, p. 480). Miami blue larval development was found to be similar to
that of other conspecific lycaenid species not tended by ants (Trager
and Daniels 2009, p. 480). Although the relationships are not
completely understood, it appears that Miami blue larvae may receive
some benefits from tending ants (e.g., potential defense from
predators) without much, if any, costs incurred.
Habitat
The Miami blue is a coastal butterfly reported to occur in openings
and around the edges of hardwood hammocks (forest habitats
characterized by broad-leaved evergreens), and in other communities
adjacent to the coast that are prone to frequent natural disturbances
(e.g., coastal berm hammocks, dunes, and scrub) (Opler and Krizek 1984,
p. 112; Minno and Emmel 1994, p. 647; Emmel and Daniels 2004, p. 12).
It also uses tropical pinelands (Minno and Emmel 1993, p. 134) and open
sunny areas along trails (Pyle 1981, p. 489). In the Keys, it was most
abundant near disturbed hammocks where weedy flowers provided nectar
(Minno and Emmel 1994, p. 647). It also occurred in pine rocklands
(fire-dependent slash pine community with palms and a grassy
understory) on Big Pine Key (Minno and Emmel 1993, p. 134; Calhoun et
al. 2002, p. 18) and elsewhere in Monroe and Miami-Dade Counties. In
Miami-Dade County, it occurred locally inland, sometimes in abundance
(M. Minno, pers. comm. 2010). Within KWNWR, all occupied areas had
coastal strands and dunes fronted by beaches (Cannon et al. 2007, p.
13; Cannon et al. 2010, p. 851).
Larval host plants include blackbead, nickerbean, balloonvine, and
presumably Acacia spp. (Dyar 1900, pp. 448-449, Kimball 1965, p. 49;
Lenczewski 1980, p. 47; Pyle 1981, p. 489; Calhoun et al. 2002, p. 18).
Gray nickerbean (Caesalpinia bonduc) is widespread and common in
coastal south Florida. Following disturbances, it can dominate large
areas (K. Bradley, The Institute for Regional Conservation [IRC], pers.
comm. 2002). Gray nickerbean has been recorded as far north as Volusia
County on the east coast, matching the historical range of the Miami
blue, and Levy County on the west coast (J. Calhoun, pers. comm.
2003b). The Miami blue is also reported to use peacock flower
(Caesalpinia pulcherrima) (Matteson 1930, pp. 13-14; Calhoun et al.
2002, p. 18), a widely cultivated exotic that occurs in disturbed
uplands and gardens (Gann et al. 2001-2010, p. 1). Rutkowski (1971, p.
137) and Opler and Krizek (1984, p. 113) reported the use of snowberry.
Brewer (1982, p. 22) reported the use of cat's paw blackbead
(Pithecellobium unguis-cati) on Sanibel Island in Lee County.
Prior to the 1970s, documented host plants for the butterfly were
nickerbean and blackbead (J. Calhoun, pers. comm. 2003b). Balloonvine
(Cardiospermum spp.) was not reported as a host plant until the 1970s,
when these plants seemed to have become common in extreme southern
Florida (J. Calhoun, pers. comm. 2003b). Subsequently, balloonvine
(Cardiospermum halicacabum), an exotic species in Florida, was the most
frequently reported host plant for Miami blue (e.g., Lenczewski 1980,
p. 47; Opler and Krizek 1984, p. 113; Minno and Emmel
[[Page 49545]]
1993, p. 134; 1994, p. 647; Calhoun et al. 2002, p. 18). However,
Carroll and Loye (2006, pp. 13-15) corrected ``the common view that a
principal host plant, balloonvine, is an exotic weed.'' They found that
published reports of Miami blue larvae on balloonvine all identified
the host as C. halicacabum and stated that the butterfly was instead
dependent upon a declining native C. corindum (Carroll and Loye 2006,
pp. 14, 23). Bradley (pers. comm. 2002) also confirmed that C.
halicacabum does not occur in the Keys, noting that the native
balloonvine (C. corindum) is relatively common and widespread in the
Keys and has been commonly mistaken as C. halicacabum in the Keys and
other sites in south Florida.
Calhoun (pers. comm. 2003b) suggested that the Miami blue may
simply utilize whatever acceptable hosts are available under suitable
conditions. According to Calhoun (pers. comm. 2003b), a review of the
historical range of the butterfly and its host plants suggests
balloonvine was a more recent larval host plant and temporarily
surpassed nickerbean as the primary host plant. As native coastal
habitats were destroyed, balloonvine readily invaded disturbed
environments, and the Miami blue used what was most commonly available.
Minno (pers. comm. 2010) suggested that the Miami blue used balloonvine
on Key Largo and Plantation Key extensively in the 1970s through the
1990s, noting that nickerbean, blackbead, and perhaps other hosts were
also probably used, but not documented.
The Miami blue metapopulation (series of small populations that
have some level of interaction) at KWNWR was found to rely upon Florida
Keys blackbead as the singular host plant (Cannon et al. 2007, p. 1;
Cannon et al. 2010, pp. 851-852). Blackbead was also an important
nectar plant when in flower. High counts of Miami blues at KWNWR were
generally associated with the emergence of flowers and new leaves on
blackbead (Cannon et al. 2007, pp. 14-15; Cannon et al. 2010, pp. 851-
852). All sites that supported Miami blues contained blackbead (Cannon
et al. 2007, p. 6; Cannon et al. 2010, p. 851). Limited abundance of
blackbead within select areas of KWNWR was thought to limit abundance
of the Miami blue (Cannon et al. 2007, p. 10; Cannon et al. 2010, p.
850). At BHSP, the Miami blue was closely associated with gray
nickerbean, but also uses blackbead (M. Minno, pers. comm. 2010). In
KWNWR, gray nickerbean was rare, with only a few small plants on Boca
Grande Key and the Marquesas Keys (Cannon et al. 2010, p. 851).
Adult Miami blues have been reported to feed on a wide variety of
nectar sources including Spanish needles (Bidens alba), Leavenworth's
tickseed (Coreopsis leavenworthi), scorpionstail (Heliotropium
angiospermum), turkey tangle fogfruit or capeweed (Lippia nodiflora),
buttonsage (Lantana involucrata), snow squarestem (Melanthera nivea [M.
aspera]), blackbead, Brazilian pepper (Schinus terebinthifolius), false
buttonweed (Spermacoce spp.), and seaside heliotrope (Heliotropium
curassavicum) (Pyle 1981, p. 489; Opler and Krizek 1984, p. 113; Minno
and Emmel 1993, p. 135; Emmel and Daniels 2004, p. 12). Emmel and
Daniels (2004, p. 12) reported that the Miami blue uses a variety of
flowering plant species in the Boraginaceae, Asteraceae, Fabaceae,
Polygonaceae, and Verbenaceae families for nectar. Cannon et al. (2010,
p. 851) found the butterfly uses nine plant species as nectar sources
within KWNWR, including: Blackbead, snow squarestem, coastal searocket
(Cakile lanceolata), black torch (Erithalis fruticosa), yellow joyweed
(Alternanthera flavescens), bay cedar (Suriana maritime), sea lavender
(Argusia gnaphalodes), seaside heliotrope, and sea purslane (Sesuvium
portulacastrum).
Nectar sources must be near potential host plants since the
butterflies are sedentary and may not travel between patches of host
and nectar sources (Emmel and Daniels 2004, p. 13). This may help
explain the absence of the Miami blue from areas in which host plants
are abundant and nectar sources are limited (J. Calhoun, pers. comm.
2003b). Emmel and Daniels (2004, p. 13) argued that it is potentially
critical that sufficient available adult nectar sources be directly
adjacent to host patches and also important that a range of potential
nectar sources be available in the event one plant species goes out of
flower or is adversely impacted by environmental factors. Cannon et al.
(2010, p. 851) suggested that the growth stage of blackbead, coupled
with abundant nectar from herbaceous plants, likely influenced Miami
blue abundance; the highest counts occurred when blackbead was
flowering profusely and producing new leaves.
Historical Distribution
The Miami blue butterfly (Cyclargus thomasi bethunebakeri) is
endemic to Florida with additional subspecies occurring in the Bahamas,
Puerto Rico, and Hispaniola (Smith et al. 1994, p. 129; Hernandez 2004,
p. 100; Saarinen 2009, pp. 18-19, 28). Field guides and other sources
differ as to whether C. thomasi bethunebakeri occurs in the Bahamas.
Clench (1963, p. 250), who collected butterflies extensively in the
West Indies, indicated that the subspecies occurred only in Florida.
Riley (1975, p. 110) and Calhoun et al. (2002, p. 13) indicated that
the Miami blue of Florida rarely occurs as a stray in the Bahamas.
Minno and Emmel (1993, p. 134; 1994, p. 647) and Calhoun (1997, p. 46)
considered the Miami blue to occur only in Florida (endemic to Florida,
with other subspecies found in the Bahamas and Greater Antilles). Smith
et al. (1994, p. 129) indicated that the Miami blue occurs in southern
Florida, but noted it has been recorded from the Bimini Islands in the
Bahamas. However, in a recent comprehensive study of museum specimens,
Saarinen (2009, p. 28) found no specimens in current museum holdings to
verify this. Overall, the majority of historical records pertaining to
this subspecies' distribution are dominated by Florida occurrences,
with any peripheral occurrences in the Bahamas possibly being ephemeral
in nature.
Although information on distribution is somewhat limited, it is
clear that the historical range of the Miami blue has been
significantly reduced. The type series (i.e., the original set of
specimens on which the description of the species is based) contains
specimens ranging from Key West up the east coast to Volusia County
(Comstock and Huntington 1943, p. 98; J. Calhoun, pers. comm., 2003b).
Opler and Krizek (1984, p. 112) showed its historical range as being
approximately from Tampa Bay and Cape Canaveral southward along the
coasts and through the Keys. It has also been collected in the Dry
Tortugas (Forbes 1941, pp. 147-148; Kimball 1965, p. 49; Glassberg and
Salvato 2000, p. 2). Lenczewski (1980, p. 47) noted that it was
reported as extremely common in the Miami area in the 1930s and 1940s.
Calhoun et al. (2002, p. 17) placed the historical limits of the
subspecies' northern distribution at Hillsborough and Volusia Counties,
extending southward along the coasts to the Marquesas Keys (west of Key
West).
The Miami blue was most common on the southern mainland and the
Keys, especially Key Largo and Big Pine Key (Calhoun et al. 2002, p.
17) and other larger keys with hardwood hammock (Monroe County) (M.
Minno, pers. comm. 2010). The subspecies was recorded on at least 10
islands of the Keys (Adams Key, Big Pine Key, Elliott Key, Geiger Key,
Key Largo, Lignumvitae Key, Old Rhodes Key, Plantation Key, Stock
Island, Sugarloaf Key) (Minno and Emmel 1993, p. 134). On the Gulf
coast, it was reportedly
[[Page 49546]]
more localized and tended to occur on more southerly barrier islands
(J. Calhoun, pers. comm. 2003b). According to Calhoun et al. (2002, p.
17), the Miami blue occupied areas on the barrier islands of Sanibel,
Marco, and Chokoloskee, along the west coast into the 1980s (based upon
Brewer 1982, p. 22; Minno and Emmel 1994, pp. 647-648). Lenczewski
(1980, p. 47) reported that the Miami blue historically occurred at
Chokoloskee, Royal Palm (Miami-Dade County), and Flamingo (Monroe
County) within ENP, but that the subspecies has not been observed in
ENP since 1972.
Based upon examination of specimens from museum collections
(N=689), Saarinen (2009, pp. 42, 55-57) found a large, primarily
coastal, geographic distribution for the butterfly. Most specimens from
an 11-county area from 1900 to 1990 were collected in Miami-Dade and
Monroe Counties (Saarinen 2009, pp. 42, 58). Records from Miami-Dade
County (N=212) were most numerous in the 1930s and 1940s; records from
Monroe County (N=387) (including all of the Florida Keys) were most
numerous in the 1970s (Saarinen 2009, pp. 42, 58). Saarinen (2009, p.
47) was not able to quantify issues of collector bias and noted that
collecting restrictions, inaccessibility of certain islands, and
targeted interest in certain areas, may have been factors influencing
the relative abundance (and distribution) of specimens collected. For
example, it is unclear whether Key Largo represented a ``central
hotspot,'' a spot simply heavily visited by lepidopterists, or both
(Saarinen 2009, p. 47). Still, it is clear that specimens were common
in museum collections from the early 1900s to the 1980s, suggesting
that the butterfly was abundant, at least in local patches, during this
time period (Saarinen 2009, p. 46). This is consistent with the work of
Carroll and Loye (2006, pp. 15-18), who, in a compilation of location
data for specimens (N=209), found that most collections were from the
Upper Keys; those from peripheral sites were generally less recent and
only single specimens. Examination of museum records further verified
the Miami blue's wide distribution in southern Florida through time
(Carroll and Loye 2006, pp. 15-18; Saarinen 2009, p. 46).
By the 1990s, very few Miami blue populations were known to
persist, and the butterfly had not been seen on the western Florida
coast since 1990, where it was last recorded on Sanibel Island (Calhoun
et al. 2002, p. 17). One of the few verifiable reports (prior to
rediscovery in 1999) was on Big Pine Key in March 1992 (Glassberg et
al. 2000, p. 79; Glassberg and Salvato 2000, p. 1; Calhoun et al. 2002,
p. 17). Following Hurricane Andrew in 1992, there were a few
unsupported reports from Key Largo and Big Pine Key and the
southeastern Florida mainland from approximately 1993 to 1998
(Glassberg and Salvato 2000, p. 3; Calhoun et al. 2002, p. 17). In
1996, four adult Miami blues were observed in the area of Dagny Johnson
Key Largo Hammock Botanical State Park (DJSP) by Linda and Byrum Cooper
(L. Cooper, listowner of LEPSrUS Web site, pers. comm. 2002; Calhoun et
al. 2002, p. 17). However, a habitat restoration project apparently
eradicated that population (L. Cooper, pers. comm. as cited in Calhoun
et al. 2002, p. 17).
The Miami blue was presumed to be extirpated until its rediscovery
in 1999 by Jane Ruffin, who observed approximately 50 individuals at a
site in the lower Keys (Bahia Honda) (Ruffin and Glassberg 2000, p. 3;
Calhoun et al. 2002, p. 17). Additional individuals were located at a
site within 0.5 mile (0.8 kilometers (km)) of where Ruffin had
discovered the population (Glassberg and Salvato 2000, p. 3). Glassberg
and Salvato (2000, p. 1) stated that more than 15 highly competent
butterfly enthusiasts had failed to find any populations of the Miami
blue from 1992 until 1999, despite more than 1,000 hours of search
effort in all sites known to harbor former colonies and other potential
sites throughout south Florida and the Keys. In May 2001, there was an
additional sighting by Richard Gillmore of a single Miami blue in the
hammocks in North Key Largo (Calhoun et al. 2002, p. 17; J. Calhoun,
pers. comm. 2003b).
Current Distribution
Numerous searches for the Miami blue have occurred in the past
decade by various parties. The Miami blue was not observed on 105
survey dates at 11 locations on the southern Florida mainland from 1990
to 2002 (Edwards and Glassberg 2002, p. 4). In the Keys, surveys during
the same time period also produced no sightings of the Miami blue at 29
locations for 224 survey dates (Edwards and Glassberg 2002, p. 4). In
2002, the Service initiated a status survey, contracting researchers at
the UF, to search areas within the subspecies' historical range,
concentrating on the extreme south Florida mainland and throughout the
Keys. Despite surveys at 45 sites during 2002-2003, adults or immature
stages were found only at a single site near BHSP on West Summerland
Key (Emmel and Daniels 2004, pp. 3-6; 21-25) (approximately 1.9 miles
[3 km] west of BHSP). The Miami blue was not found on the mainland,
including Fakahatchee Strand, Charles Deering Estate, ENP, Marco
Island, or Chokoloskee (Emmel and Daniels 2004, pp. 5-6, 25). It was
also absent from the following locations in the Keys: Elliott, Old
Rhodes, Totten, and Adams Key in Biscayne National Park (BNP) and Key
Largo and Plantation Key in the Upper Keys; Lignumvitae, Lower
Matecumbe, Indian, and Long Keys in the Middle Keys; and Little Duck,
Missouri, Ohio, No Name, Big Pine, Ramrod, Little Torch, Wahoo, Cudjoe,
Sugarloaf, and Stock Island in the Lower Keys (Emmel and Daniels 2004,
pp. 3-5; 21-24).
Based upon an additional independent survey in 2002, the Miami blue
was also not found at 18 historical locations where it had previously
been observed or collected in Monroe, Broward, Miami-Dade, and Collier
Counties into the 1980s (D. Fine, unpub. data, pers. comm. 2002). These
were: Cactus Hammock (Big Pine Key), County Road (Big Pine Key), Grassy
Key, John Pennekamp Coral Reef State Park, Windley Key, Crawl Key,
Stock Island, Plantation Key, and Lower Matecumbe Key in Monroe County;
Hugh Taylor Birch State Park and Coral Springs in Broward County;
Redlands, IFAS Station, Frog City, and Card Sound Road in Miami-Dade
County; Marco Island and Fakahatchee Strand State Preserve in Collier
County.
In 2003, the Service contracted the North American Butterfly
Association (NABA) to perform systematic surveys in south Florida and
the Keys to identify all sites at which 21 targeted butterflies,
including the Miami blue, could be found. Despite considerable survey
effort (i.e., 187 surveys performed), the Miami blue was not located at
any location except Bahia Honda (NABA 2005, pp. 1-7). In addition, the
Miami blue was not present within the J.N. Ding Darling National
Wildlife Refuge or on Sanibel-Captiva Conservation Foundation
properties (both on Sanibel Island), during annual surveys conducted
from 1998 to 2009 (M. Salvato, pers. comm. 2011a). Monthly or quarterly
surveys of Big Pine Key, conducted from 1997 to 2010, failed to locate
Miami blues (M. Salvato, pers. comm. 2011b). Minno and Minno (2009, pp.
77, 123-193) failed to locate the subspecies during butterfly surveys
throughout the Keys conducted from August 2006 to July 2009.
Although two fifth-instar larvae were documented on West Summerland
Key in November 2003, on unprotected land approximately 2.2 miles (3.6
km) west of BHSP (Emmel and Daniels 2004, pp. 3, 24, 26), none have
been seen there
[[Page 49547]]
since. According to Daniels (pers. comm. 2003c), an adult (or adults)
was likely blown to this key from Bahia Honda by strong winds or was at
least partially assisted by the wind.
In November 2006, Miami blues were discovered on islands within
KWNWR (Cannon et al. 2007, p. 2). This discovery was significant
because it was a new, geographically separate population, and doubled
the known number of metapopulations remaining (to 2). During the period
from 1999 to 2009, the Miami blue was consistently found at BHSP
(Ruffin and Glassberg 2000, p. 29; Edwards and Glassberg 2002, p. 9;
Emmel and Daniels 2009, p. 4; Daniels 2009, p. 3). However, this
population may now be extirpated. This leaves the islands within KWNWR
as the only known locations of the subspecies.
Overall, the Miami blue has undergone a substantial reduction in
its historical range, with an estimated > 99 percent decline in area
occupied (Florida Fish and Wildlife Conservation Commission [FWC] 2010,
p. 11). In 2009, metapopulations existed at two main locations: BHSP
and KWNWR, roughly 50 miles (80 km) apart. The metapopulation at BHSP
is now possibly extirpated with the last adult documented in July 2010
(A. Edwards, Florida Atlantic University, pers. comm. 2011). It is
feasible that additional occurrences exist in the Keys, but these may
be ephemeral and low in population number (Saarinen 2009, p. 143). In
2010, the Service funded an additional study with UF to search remote
areas for possible presence; this study is now underway. The subspecies
was not located in limited surveys conducted in the Cape Sable area of
ENP in March 2011 (P. Halupa, pers. obs. 2011; M. Minno, pers. comm.
2011).
Bahia Honda State Park
Bahia Honda is a small island at the east end of the lower Keys,
approximately 7.0 miles (11.3 km) west of Vaca Key (Marathon) and 2.0
miles (3.2 km) east of Big Pine Key. The amount of suitable habitat
(habitat supporting larval host plants and adjacent adult nectar
sources) within BHSP is approximately 1.5 acres (0.6 hectares [ha]). Of
the suitable habitat available at BHSP, approximately 85 percent (1.3
acres [0.5 ha]) was occupied by the Miami blue (Emmel and Daniels 2004,
p. 12). The metapopulation comprised 13 distinct colonies, with the
core comprising 3 or 4 colonies, located at the southwest end (Emmel
and Daniels 2004, pp. 6, 27). This area contained the largest
contiguous patch of host plants, although the size was estimated to be
0.8 acres (0.32 ha) (Emmel and Daniels 2004, p. 12). The second largest
colony occurred at the opposite (northeast) end of BHSP and was based
solely on the presence of two to three small, isolated patches of
nickerbean directly adjacent to an existing nature trail and parking
area (Emmel and Daniels 2004, p. 6). The remaining colonies were
isolated, with most occurring in close proximity to the main park road
(Emmel and Daniels 2004, pp. 13, 27). Isolated colonies used very small
patches of nickerbean (e.g., one was estimated to be 10 by 10 feet [3
by 3 meters]) (Emmel and Daniels 2003, p. 3), often adjacent to paved
roads (Emmel and Daniels 2004, pp. 6, 12, 27).
Key West National Wildlife Refuge
Efforts to define the limits of the KWNWR metapopulation were
conducted from November 2006 to July 2007 (Cannon et al. 2007, pp. 10-
11; 2010, p. 849). Miami blues were found in seven sites on five
islands in the Marquesas Keys, approximately 12.2 miles (19.6 km) west
of Key West, and on Boca Grande Key, approximately 11.8 miles (19 km)
west of Key West (6.3 miles [10.1 km] east-southeast of the Marquesas
Keys) (Cannon et al. 2007, pp. 1-24; 2010, pp. 847-848). The eight
sites occupied by Miami blues ranged from approximately 0.25 to 37.10
acres (0.1-15.0 ha) (Cannon et al. 2007, p. 6; 2010, p. 848). The
combined amount of upland habitat of occupied sites (within KWNWR) was
roughly 59 acres (23.8 ha) (Cannon et al. 2010, p. 848). Miami blues
were not found on Woman Key, approximately 10.1 miles (16.2 km) west of
Key West, or Man Key, approximately 6.8 miles (10.9 km) west of Key
West; these sites had abundant nectar plants, but few host plants
(Cannon et al. 2007, pp. 5, 12; 2010, pp. 848-850). In addition, the
Miami blue was not found on six islands in the Great White Heron
National Wildlife Refuge (GWHNWR); these sites contained limited
amounts of, or were lacking, either host plants or nectar plants
(Cannon et al. 2007, pp. 5, 12; 2010, pp. 847, 850-851).
In a separate study, Daniels also found four of the sites
previously occupied within KWNWR to support the Miami blue variously
from 2008 to 2010 (Emmel and Daniels 2008, pp. 7-10; 2009, pp. 9-13;
Daniels 2008, pp. 1-6; Daniels 2010, pp. 3-5; J. Daniels, pers. comm.
2010a). Survey effort, however, was limited. Some previously occupied
islands were not searched, and no new occupied areas were identified.
Followup presence and absence surveys by KWNWR in 2009 showed that
the Miami blue was present on two sites in the Marquesas, but not on
Boca Grande (P. Cannon, pers. comm. 2010a). In 2010, similar surveys
indicated that the Miami blue was present on Boca Grande and one site
in the Marquesas; it was still not located on Woman Key (P. Cannon,
pers. comm. 2010b; T. Wilmers, pers. comm. 2010a). In March and April
2011, Miami blues were still present on five of seven sites where
previously found in KWNWR (T. Wilmers pers. comm. 2011a; N. Haddad,
North Carolina State University [NCSU], pers. comm. 2011).
Reintroductions
Although Miami blue butterflies were successfully reared in
captivity, reintroductions have been unsuccessful. Since 2004,
approximately 7,140 individuals have been released (J. Daniels pers.
comm. as cited in FWC 2010, p. 8). Between August 2007 and November
2008, reintroduction events were carried out at BNP and DJSP 12 times
resulting in the release of 3,553 individuals (276 adults/3,277 larvae)
(Emmel and Daniels 2009, p. 4). Monitoring efforts have been limited;
19 days were spent monitoring reintroduction sites (Emmel and Daniels
2009, p. 4). To date, no evidence of colony establishment has been
found (Emmel and Daniels 2009, p. 4). It is not clear why
reintroductions were unsuccessful. Numerous factors may have been
involved (e.g., predation, parasitism, insufficient host plant or
larval sources). Due to limited resources and other constraints,
standard protocols were not employed to help identify factors that may
have influenced reintroduction success. Research with surrogate species
may be helpful to better establish protocols and refine techniques for
the Miami blue prior to future propagation and reintroduction efforts.
Population Estimates and Status
Bahia Honda State Park metapopulation
Prior to its apparent extirpation, the metapopulation at BHSP was
monitored regularly from 2002 to 2009 (Emmel and Daniels 2009, p. 4).
Pollard transects at the south-end colony site (largest) yielded annual
peak counts of approximately 175, 84, 112, and 132, from 2002 to 2005
(prior to hurricanes), and 82, 81, 120, and 38, from 2006 to 2009
(Emmel and Daniels 2009, p. 4). From October 2002 to September 2003,
abundance estimates using mark-release-recapture (Schnabel method)
ranged from a low of 19.7 in February 2003 to a high of 114.5 in June
2003
[[Page 49548]]
(Emmel and Daniels 2004, p. 9). Counts ranged from 6 to 100 adults
during surveys by the NABA conducted from February 2004 to January 2005
(NABA 2005, unpub. data). Monthly (2003 to 2006) or bimonthly (2007)
monitoring by Salvato (pers. comm. 2011c) at the south-end colony
produced annual average counts of 129, 58, 46, 6, and 8, respectively,
from 2003 to 2007. Salvato (pers. comm. 2011c) observed 21, 10, and 0
Miami blues from 2008 to 2010, respectively, based on limited surveys.
In general, early (dry) season numbers were low in most years and
were attributed to a persistent south Florida drought (Emmel and
Daniels 2009, p. 4). Abundance trends indicated that there was a marked
decrease in the number of individuals during the winter months
(November to February) (Emmel and Daniels 2004, p. 9; 2009, p. 4).
Higher abundances during the summer wet season may relate to production
of a large quantity of new terminal growth on the larval host plants
(nickerbean) and availability of nectar sources from spring rainfall
(Emmel and Daniels 2004, pp. 9-11).
Four hurricanes affected habitat at BHSP in 2005, resulting in
reduced abundance of Miami blue following subsequent storms that
continued throughout 2006 (Salvato and Salvato 2007, p. 160). Although
no quantitative measures were taken, a significant portion of the
nickerbean in the survey area (> 35 percent of the area of available
habitat) was damaged by the storms; roughly 60-80 percent of the
vegetation on the southern side of the island was visually estimated to
have been heavily damaged, including large stands of host and nectar
plants (Salvato and Salvato 2007, p. 156). Despite a decline in
abundance after the hurricanes, the Miami blue had appeared to rebound
toward pre-storm abundance by the summer months of 2007 (Salvato and
Salvato 2007, p. 160). However, peaks remained below those found prior
to the 2005 hurricane season (Emmel and Daniels 2009, p. 4).
Although it is unclear when iguanas became established at BHSP,
effects of herbivory on the host plant were apparent by late 2008 or
early 2009 (Emmel and Daniels 2009, p. 4; Daniels 2009, p. 5; P.
Cannon, pers. comm. 2009; A. Edwards, pers. comm. 2009; P. Hughes,
pers. comm. 2009; M. Salvato, pers. comm. 2010a). Defoliation was
mostly limited to the south-end colony site (Emmel and Daniels 2009, p.
4). Cooperative eradication efforts to address this problem began in
2009 and continue today; however, iguanas continue to impact terminal
nickerbean growth (see Summary of Factors Affecting the Species) (Emmel
and Daniels 2009, p. 4; Daniels 2009, p. 5; E. Kiefer, BHSP, pers.
comm. 2011a). From 2006 through 2009, adult or immature Miami blues
were found at several colony sites; however, one colony became
relatively unproductive in 2005 (pre-hurricane) (Emmel and Daniels
2009, p. 4). No Miami blues have been found at any roadway nickerbean
patches within BHSP since 2005, prior to the advent of profound iguana
herbivory and damages from hurricanes (Emmel and Daniels 2009, p. 4).
The metapopulation has diminished in recent years likely due to the
combined effects of small population size, drought, cold temperatures,
and iguanas (see Summary of Factors Affecting the Species). In 2010,
few Miami blues were observed at BHSP. On January 23, 2010, a
photograph was taken of a pair of Miami blues mating (Olle 2010, p. 5).
On February 12, 2010, a photograph was taken of a single adult (C.
DeWitt, pers. comm. 2011). In March 2010, Daniels found one larva, but
no adults (D. Cook, FWC, pers. comm. 2010a). In July 2010, a single
adult was observed and photographed (A. Edwards, pers. comm. 2011). No
Miami blue adults have been located during quarterly surveys conducted
in 2010 by Salvato (pers. comm. 2010b, 2011c). No Miami blue
butterflies of any life stage were subsequently seen despite frequent
searches (D. Cook, pers. comm. 2010a; P. Cannon, pers. comm. 2010c,
2010d, 2010e, 2010f; M. Salvato, pers. comm. 2011c, 2011d; Jim
Duquesnel, BHSP, pers. comm. 2011a, 2011b).
Key West National Wildlife Refuge Metapopulation(s)
The metapopulation at KWNWR yielded counts of several hundred, at
various times, in 2006-2007. Checklist counting was used during surveys
conducted between November 2006 and July 2007 to document the
distribution and abundance of Miami blues (Cannon et al. 2007, p. 5;
2010, p. 848). Within the seven sites occupied in the Marquesas Keys,
the highest counts ranged from 8 to 521 depending upon site and
sampling date (Cannon et al. 2007, p. 7; 2010, p. 848). The highest
count on Boca Grande was 441 in February 2007 (Cannon et al. 2007, p.
7; 2010, p. 848). Highest counts occurred when blackbead flowered
profusely and produced new leaves (Cannon et al. 2010, p. 851). In
March and April, blackbead was observed to yield little new growth and
no flowering, and oviposition by Miami blues was not observed (Cannon
et al. 2007, p. 8). Partial searches on two islands in May and June
revealed few Miami blues; little new leaf growth and no flowering of
blackbead was observed at these locations after February 2007 (Cannon
et al. 2010, p. 850). Seasonality observed on KWNWR was different than
that described for the BHSP metapopulation (above). Hurricane Wilma
(October 2005) heavily damaged or killed blackbead stands at most
sites, but it also likely enhanced foraging habitat, if only
temporarily, on select islands within the KWNWR (Cannon et al. 2007, p.
10; 2010, p. 851) (see Summary of Factors Affecting the Species).
Periodic surveys at KWNWR in 2008 and 2009 suggested lower levels
of abundance, based upon limited effort (Emmel and Daniels 2008, pp. 7-
10; 2009, pp. 9-13). In February 2008, researchers recorded 3 adults on
Boca Grande and a total of 32 adults at two islands within the
Marquesas; lack of rainfall resulted in very limited adult nectar
sources and limited new growth of larval host (Emmel and Daniels 2008,
pp. 7-8). In April 2008, one adult was recorded on Boca Grande; one
adult was also recorded at another island (Emmel and Daniels 2008, p.
8). In June 2008, no adults were located on Boca Grande, and a total of
27 were recorded from two other islands (Emmel and Daniels 2008, p. 9).
In August 2008, no adults were found at Boca Grande, and five adults
were recorded at another island (Emmel and Daniels 2008, p. 10). In
March 2009, no adults were recorded on Boca Grande; habitat conditions
were deemed very poor, with limited new host growth and available
nectar resources (Emmel and Daniels 2009, p. 12). In April 2009,
researchers found a total of 22 adults from two islands within the
Marquesas (Emmel and Daniels 2009, p. 13).
Based upon limited data and observations, the Miami blue persisted
on various islands within the KWNWR in 2010. From April through July
2010, the Miami blue was observed on 5 of 10 dates at one location
within the Marquesas, although in limited numbers during brief surveys
(T. Wilmers, pers. comm. 2010b). On July 28, 2010, researchers recorded
19 adults from three islands within the Marquesas, in limited surveys;
another 25 adults were recorded on Boca Grande in less than 1 hour of
survey work (J. Daniels, pers. comm. 2010a). On September 30, 2010,
dozens of Miami blues were observed on Boca Grande; this may have
represented an actual population size in the hundreds (N. Haddad, pers.
comm. 2010). On November 24, 2010, researchers positively identified 48
Miami blue adults on Boca Grande in less than 3 hours of surveys,
noting that assessment was difficult due to the
[[Page 49549]]
many hundreds or possibly thousands of cassius blues, which were also
present (P. Cannon, pers. comm. 2010b; T. Wilmers, pers. comm. 2010a).
In March and April 2011, researchers observed Miami blue adults at five
sites within KWNWR in numbers similar to those reported above (N.
Haddad, pers. comm. 2011). In July 2011, fewer adults were observed (P.
Hughes, pers. comm. 2011).
At this time, it is unclear what the size of the metapopulation at
KWNWR is or its dynamics. However, available data (given above) suggest
wide fluctuations of adults within and between years and sites. The
frequency of dispersal between islands is also not known (Cannon et al.
2010, p. 852). Due to the distance between the Marquesas and Boca
Grande (i.e., about 7 miles [11 km]) and the species' limited dispersal
capabilities, it is possible that two (or more) distinct
metapopulations exist within KWNWR (J. Daniels, pers. comm. 2010b). In
September 2010, the Service initiated a new study with researchers from
NCSU to conduct a comprehensive examination of potential habitat within
KWNWR and GWHNWR, quantify current distribution and habitat use, and
develop a monitoring protocol to estimate detectability, abundance, and
occupancy parameters.
Gene Flow and Genetic Diversity Within Contemporary Populations
Saarinen (2009, pp. 15, 29-33, 40, 44) and Saarinen et al. (2009b,
pp. 242-244) examined 12 polymorphic microsatellite loci (noncoding
regions of chromosomes) to assess molecular diversity and gene flow of
wild and captive-reared Miami blue butterflies; also, one
microsatellite locus was successfully amplified from a subset of the
museum specimens. Although results from historical specimens should be
interpreted with caution (due both to small sample size and the single
microsatellite locus), Saarinen (2009, pp. 15, 50-51) reported some
loss of diversity in the contemporary populations, though less than had
been expected. Even with small sample sizes, historical populations
were significantly more diverse (with generally higher effective
numbers of alleles and observed levels of heterozygosity) than BHSP;
KWNWR population values were between historical values and BHSP values
(Saarinen 2009, pp. 44-46).
Both historical and contemporary populations showed evidence of a
metapopulation structure with interacting subcolonies (E.V. Saarinen
and J.C. Daniels, unpub. data as cited in Saarinen 2009, p. 49).
However, the metapopulations at BHSP and KWNWR are separated by a
distance of more than 43 miles (70 km). Given the Miami blue's poor
dispersal capabilities (E.V. Saarinen and J.C. Daniels, unpub. data as
cited in Saarinen 2009, p. 22), it is highly unlikely that they
interacted. Saarinen's work showed no gene flow and a clear distinction
between the BHSP and KWNWR metapopulations (Saarinen 2009, pp. 36, 74,
89) (see Summary of Factors Affecting the Species).
Studies addressing molecular diversity at BHSP showed the effective
number of alleles remained relatively constant over time, at both a
monthly (generational) and annual scale (Saarinen 2009, pp. 71, 84).
Allelic (gene) richness was also stable over time in BHSP, with values
ranging from 2.988 to 3.121 when averaged across the 12 microsatellite
loci from September 2005 to October 2006. These values were lower than
those in KWNWR [3.790] (Saarinen 2009, p. 71). However, data showed
that the BHSP metapopulation retained an adequate amount of genetic
diversity to maintain the population in 2005 and 2006, despite
perceived changes in overall population size (Saarinen 2009, p. 77). No
significant evidence of a recent genetic bottleneck was found in the
BHSP generations analyzed, however, there may have been a previous
bottleneck that was undetectable with methods used (Saarinen 2009, pp.
72, 85, 141).
To explore the level of gene flow and connectivity between discrete
habitat patches at BHSP, Saarinen (2009, pp. 64-65) conducted analyses
at several spatial scales, analyzing BHSP as a single population (with
no subdivision), as individual colonies occupying discrete habitat
patches (as several groups acting in a metapopulation structure), and
as a division of clumped colonies versus other, more spatially distant
colonies. Analyses of microsatellite frequencies were also used to
assess gene flow between habitat patches (Saarinen 2009, p. 72). While
some subpopulations were well linked, others showed more division
(Saarinen 2009, p. 73). High levels of gene flow (and relatively little
differentiation) were apparent even between distant habitat patches on
BHSP, and the smaller patches, such as those along the Main Road,
appeared to be important links in maintaining connectivity (Saarinen
2009, pp. 78, 141). Overall, gene flow between habitat patches on BHSP
was considered crucial to maintain genetic diversity and imperative for
the Miami blue's long-term persistence at this location (Saarinen 2009,
p. 141).
The metapopulation structure on KWNWR is more extensive than that
which occurred at BHSP (Saarinen 2009, p. 49). Due to small sample
sizes from Boca Grande, only samples from the Marquesas Keys were used
for genetic analysis of KWNWR, and results were limited (Saarinen 2009,
pp. 66, 72). Overall, this metapopulation was found to have higher
genetic diversity (mean observed heterozygosity of 51 percent versus
39.5 percent) than the BHSP population (Saarinen 2009, p. 49). Allelic
richness (3.790 in February 2008) was also higher in KWNWR (Saarinen
2009, pp. 71, 75). Accordingly, KWNWR is a particularly important
source of variation to be considered for future conservation efforts
for this taxon (Saarinen 2009, pp. 71, 75), especially if this is the
only extant metapopulation(s) remaining. The KWNWR metapopulation
showed signs of a bottleneck and may support the hypothesis that it is
a newly founded population (Saarinen 2009, pp. 76, 141). Further work
is needed to better understand the metapopulation dynamics and genetic
implications in this population.
Previous Federal Action
On May 22, 1984, we published a Review of Invertebrate Wildlife for
Listing as Endangered or Threatened Species (49 FR 21664), which
included the Miami blue butterfly (Hemiargus thomasi bethune-bakeri) as
a category 2 candidate species for possible future listing as
threatened or endangered. Category 2 candidates were those taxa for
which information contained in our files indicated that listing may be
appropriate, but for which additional data were needed to support a
listing proposal. In a January 6, 1989, Animal Notice of Review (54 FR
572), the Miami blue butterfly continued as a category 2 candidate,
with a name change from bethune-bakeri to bethunebakeri. On November
21, 1991, the Miami blue was downgraded from a category 2 to category
3C species in an Animal Candidate Review for Listing as Endangered or
Threatened Species (56 FR 58830), characterized as having an unknown
trend (meaning additional survey work was required to determine the
current trend). Category 3C species were those taxa that had proved to
be more abundant or widespread than previously believed and/or those
that were not subject to any identifiable threat. In 1996, Category 3
species were removed from the candidate list (61 FR 7596).
On June 15, 2000, we received a petition from the NABA and Mark
Salvato to emergency list the Miami
[[Page 49550]]
blue butterfly (Hemiargus thomasi bethunebakeri) as endangered with
critical habitat pursuant to the Act. The petition cited habitat loss
and fragmentation, influence of mosquito control chemicals, unethical
butterfly collection, and human-caused changes to habitat occupied by
the subspecies' only known population.
On August 29, 2001, the Department of the Interior reached an
agreement with several conservation organizations regarding a number of
listing actions that had been delayed by court-ordered critical habitat
designations and listing actions for other species. That agreement was
subsequently approved by the U.S. District Court for the District of
Columbia. Under the agreement, we and the conservation organizations
agreed to significantly extend the actions on the other species,
thereby making funds available for a number of listing actions judged
to be higher priority. Those higher priority listing actions included
the 90-day finding for the petition to list the Miami blue butterfly.
On January 3, 2002 (67 FR 280), we announced our 90-day finding for
the petition to list the Miami blue, initiated a status review, and
sought data and information from the public. In this finding, we
indicated the Miami blue may be in danger of extirpation. However, we
did not believe the threats to be so great that extirpation was
imminent, requiring us to provide emergency protection to the butterfly
through our emergency listing provisions. We indicated that we could
issue an emergency rule when an immediate threat posed a significant
risk to the well-being of the subspecies.
On May 11, 2005, we recognized the Miami blue butterfly as a
Federal candidate subspecies in our annual Candidate Notice of Review
(70 FR 24872). This action constituted a 12-month finding for the
subspecies in which it was determined that the subspecies was warranted
but precluded for listing by other higher priority listing actions. On
November 9, 2009, in our annual Candidate Notice of Review (74 FR
57809), we changed the Listing Priority Number (LPN) for the Miami blue
from 6 to 3 due to increased and more immediate threats.
On August 10, 2010, the Service received a renewed petition from
the NABA for emergency listing of the Miami blue butterfly as
endangered. This petition stated that the entire remaining population
is in significant and immediate danger because it exists in a single
location and is subject to hurricanes, iguanas, and human impacts given
that the area is remote and difficult to patrol. On January 11, 2011,
the Service received a separate petition for emergency listing of the
Miami blue butterfly with critical habitat from the Center for
Biological Diversity.
The Miami blue butterfly is currently a Federal candidate (LPN of
3) and State-threatened subspecies.
The Service's decision to emergency list the Miami blue butterfly
resulted from our careful review of the status of the subspecies and
the threats it faces. We based this decision on information in our
files or otherwise available to us (including the results of recent
status surveys) as well as information contained in the original
petition (2000), the renewed petition (2010), the new petition (2011),
and information referenced in the petitions.
The proposed rule to list the Miami blue butterfly as endangered is
published concurrently with this emergency rule and found in this issue
of the Federal Register in Proposed Rules.
Summary of Factors Affecting the Species
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may determine a species to
be endangered or threatened due to one or more of the following five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination. Each of these
factors is discussed below.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
The Miami blue has experienced substantial destruction,
modification, and curtailment of its habitat and range (see Background,
above), with an estimated > 99 percent decline in area occupied (FWC
2010, p. 11). Although many factors likely contributed to its decline,
some of which may have operated synergistically, habitat loss,
degradation, and fragmentation are undoubtedly major forces that
contribute to its imperilment (Calhoun et al. 2002, pp. 13-19; Saarinen
2009, p. 36).
Human Population Growth and Development
The geographic range of this butterfly once extended from the Dry
Tortugas north along the Florida coasts to about St. Petersburg and
Daytona. It was most common on the southern mainland and the Keys, and
more localized on the Gulf coast. Examination of museum collections
indicated that specimens were common from the early 1900s to the 1980s;
the butterfly was widely distributed, existing in a variety of
locations in southern Florida for decades (Saarinen 2009, p. 46).
However, through time, much of this subspecies' native habitat has been
lost, degraded, or fragmented, especially on the mainland, largely from
development and urban growth (Lenczewski 1980, p. 47; Minno and Emmel
1994, pp. 647-648; Calhoun et al. 2002, p. 18; Carroll and Loye 2006,
p. 25).
On the east coast of Florida, the entire coastline in Palm Beach,
Broward, and Miami-Dade Counties (as far south as Miami Beach) is
densely urban, with only small remnants of native coastal vegetation
conserved in fragmented natural areas. Most of the Gulf Coast barrier
islands that previously supported the Miami blue, including Marco and
Chokoloskee Islands, have experienced intense development pressure and
undergone subsequent habitat loss (Calhoun et al. 2002, p. 18). In an
independent survey of historical sites where the Miami blue had
previously been observed or collected, half were found to be developed
or no longer supporting host plants in 2002 (D. Fine, unpub. data,
pers. comm. 2002).
Significant land use changes have occurred through time in south
Florida. Considering political and economic structure and changes,
Solecki (2001, pp. 339-356) divided Florida's land-use history into
three broad eras: Frontier era (1870-1930), development era (1931-
1970), and globalization era (1971-present). Within the development
era, Solecki (2001, p. 350) noted that: ``Tremendous change took place
from the early 1950s to the early and mid-1970s. Between 1953 and 1973,
nearly 5,800 km\2\ (28, 997 ha/year) of natural areas were lost to
agricultural and urban land uses (Solecki and Walker, 2001).'' During
this time, ``an almost continuous strip of urban development became
present along the Atlantic coast'' and ``urban land uses became well
established in the extreme southeastern part of the region particularly
around the cities of Miami and Fort Lauderdale, and along the entire
coastline heading northward to West Palm Beach.''
[[Page 49551]]
Saarinen (2009, pp. 42, 46) examined museum collections in the
context of Solecki's development eras and found that Miami blue records
for Miami-Dade County were highest in the 1930s and 1940s, prior to
massive land use changes and urbanization. Records from Monroe County
(including the Keys) were most numerous in the 1970s (Saarinen 2009, p.
46). Calhoun (pers. comm. 2003b) suggested the butterfly reached peak
abundance when balloonvine invaded clearings associated with the
construction boom of the 1970s and 1980s in the northern Keys and
southern mainland and became available as a suitable host plant. If so,
this may have represented a change in primary host plant at a time when
the subspecies was beginning to decline due to continued development
and destruction of coastal habitat. Saarinen (2009, p. 46) could not
correlate decreases in natural land areas with changes in the numbers
collected (or abundance), due to several confounding factors (e.g.,
increased pesticide use, exotic species). Calhoun et al. (2002, p. 13)
also attributed the butterfly's decline to loss of habitat due to
coastal development, but acknowledged that other factors such as
succession, tropical storms, and mosquito control also likely
exacerbated the decline (see Factor E).
Habitat loss and human population growth in coastal areas on the
mainland and the Keys is continuing. Human population in south Florida
has increased from less than 20,000 people in 1920 to more than 4.6
million by 1990 (Solecki 2001, p. 345). Monroe County and Miami-Dade
County, two areas where the butterfly was historically abundant, have
increased from less than 30,000 and 500,000 people in 1950,
respectively, to more than 73,000 and 2.5 million in 2009 (http://quickfacts.census.gov). All available vacant land in the Keys is
projected to be consumed by human population increases (i.e.,
developed) by 2060, including lands not accessible by automobile (Zwick
and Carr 2006, p. 14). Scenarios developed by Massachusetts Institute
of Technology (MIT) urban studies and planning department staff
(Flaxman and Vargas-Moreno 2010, pp. 3-4) include both trend and
doubling population estimates combined with climate change factors (see
below) and show significant impacts on remaining conservation lands,
including the refuges, within the Keys. While the rate of development
in portions of south Florida has slowed in recent years, habitat loss
and degradation, especially in desirable coastal areas, continues and
is expected to increase.
Although extensive loss and fragmentation of habitat has occurred,
significant areas of suitable larval host plants still remain on
private and public lands. Results from surveys (2002-2003) within south
Florida and the Keys showed that numerous areas still contained host
plants (Emmel and Daniels 2004, pp. 3-6). Results from similar surveys
in 2007-2009 suggested that 14 of 16 sites on the mainland and 20 of 22
in the Keys contained suitable habitat (Emmel and Daniels 2009, pp. 6-
8). Other researchers noted that larval host plants are common in the
Keys (Carroll and Loye 2006, p. 24; Minno and Minno 2009, p. 9). A
search of The Institute for Regional Conservation's (IRC) database
suggests that 79 conservation areas in south Florida contain
Caesalpinia spp., 39 areas contain Cardiospermum spp., and 77 contain
Pithecellobium spp. (http://www.regionalconservation.org/ircs/database/search). With significant areas of host plants still remaining in
portions of the butterfly's range, there is potential for additional
populations of the Miami blue to exist.
Acute habitat fragmentation has apparently severely diminished the
butterfly's ability to repopulate formerly inhabited sites or to
successfully locate host plants in new areas (Calhoun et al. 2002, p.
18). Although larval host plants remain locally common, the
disappearance of core populations and extent of habitat fragmentation
may now prevent the subspecies from colonizing new areas (J. Calhoun,
pers. comm. 2003b). The Miami blue is sedentary and not known to travel
far from pockets of larval host plants and adult nectar sources (J.
Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, p. 6, 13). The
presence of adult nectar sources proximal to larval host plants is
critical to the Miami blue and may help explain its absence from areas
that contain high larval host plant abundance but few nectar sources
(J. Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, p. 13).
Land Management Practices
Land management practices that remove larval host plants and nectar
sources can be a threat to the Miami blue. Some actions on public
conservation lands may have negatively affected occupied habitat, but
the extent of this impact is not known. For example, the Miami blue had
been sighted in DJSP in 1996, but following removal of balloonvine as
part of routine land management, no adults were observed (L. Cooper,
pers. comm. 2002; J. Calhoun, pers. comm. 2003b; M. Salvato, pers.
comm. 2003). In 2001, following the return of balloonvine, a single
adult was observed (J. Calhoun, pers. comm. 2003b). Calhoun noted that
the silver-banded hairstreak (Chlorostrymon simaethis), which also
feeds on balloonvine, had also returned to the site. The silver-banded
hairstreak has rebounded substantially on northern Key Largo within
disturbed areas of DJSP; if any extant Miami blues remain on the
island, reestablishment in this area is possible.
Removal of nickerbean as part of trail maintenance and impacts to a
tree resulting from placement of a facility may have impacted the south
colony at BHSP in 2002 (J. Daniels, pers. comm. 2002a; P. Halupa, pers.
obs. 2002). The tree was an apparent assembly area for display by
butterflies during courtship (J. Daniels, pers. comm. 2002a). Damage to
host plant and nectar sources from trimming and mowing during the dry
season and herbivory by iguanas (see Factor E) impacted habitat
conditions at BHSP in 2010 (D. Olle, NABA, pers. comm. 2010). More
recently, the Florida Department of Environmental Protection (FDEP) has
worked to improve habitat conditions at BHSP through plantings,
modification of its mowing practices, removal of iguanas, protection of
sensitive areas, and other actions (R. Zambrano, FWC, pers. comm. 2010;
D. Cook, pers. comm. 2010a, 2010b; Janice Duquesnel, Florida Park
Service [FPS], pers. comm. 2010a, 2010b; Jim Duquesnel, pers. comm.
2010, 2011b; E. Kiefer, pers. comm. 2011a).
Maintenance, including pruning of host vegetation along trails and
roadsides, use of herbicides, and impacts from other projects could
lead to direct mortality in occupied habitats (Emmel and Daniels 2004,
p. 14). Habitat previously supporting immature stages of the butterfly
on West Summerland Key is subject to periodic mowing for road
maintenance by Florida Department of Transportation (FDOT) (J. Daniels,
pers. comm. 2003c); the butterfly no longer occurs at this location
(Emmel and Daniels 2004, p. 3; 2009, p. 8). Since Miami blues are
sedentary with limited dispersal capabilities, alteration of even small
habitat patches may be deleterious.
Removal of host plants from conservation lands does not appear to
be occurring on any large scales at this time. IRC has conducted
extensive plant inventories on conservation lands within south Florida
and is not aware of any attempts to eradicate balloonvine and notes
that gray nickerbean has only rarely been controlled (i.e.,
purposefully removed or pruned, followed with
[[Page 49552]]
herbicide treatment) (K. Bradley, pers. comm. 2002). Nickerbean is
reported to occur in all of the State parks in the Keys. It is not
removed, but where it is a safety hazard for visitors such as when
overgrowing into trails, it is trimmed (Janice Duquesnel, pers. comm.
2003). Removal of host plants in or near occupied habitat remains a
concern, given the subspecies' small population size, isolated
occurrences, and limited dispersal capabilities (see Factor E).
Lack of prescribed fire on public lands may have adversely affected
the Miami blue through time, but impacts are unclear. In addition to
being found within coastal areas and hardwood hammocks, the Miami blue
was also known to occur within tropical pinelands, a fire-dependent
habitat (Minno and Emmel 1993, p. 134; Calhoun et al. 2002, p. 18).
Calhoun et al. (2002, p. 18) reported that, until the early 1990s, the
Miami blue most commonly occurred within pine rocklands on Big Pine
Key. In the absence of fire, pine rockland often progresses to hardwood
hammock. Lack of fire may have resulted in habitat loss, however, the
extent that this condition occurred is unclear and difficult to assess.
Since the Miami blue is sedentary, changes in vegetation due to this
and other land management practices may have exacerbated the effects of
fragmentation.
In summary, a variety of land management practices on public lands
(e.g., removal of host plants, mowing of nectar sources, and lack of
prescribed fires) may have adversely affected the Miami blue and its
habitat historically and continues to do so currently.
Climate Change and Sea Level Rise
Climatic changes, including sea level rise, are major threats to
south Florida, including the Miami blue and its habitat. Known
occurrences and suitable habitat are in low-lying areas and will be
affected by rising sea level. In general, the Intergovernmental Panel
on Climate Change (IPCC) reported that the warming of the world's
climate system is unequivocal based on documented increases in global
average air and ocean temperatures, unprecedented melting of snow and
ice, and rising average sea level (IPCC 2007, p. 2; 2008, p. 15). Sea
level rise is the largest climate-driven challenge to low-lying coastal
areas and refuges in the subtropical ecoregion of southern Florida
(U.S. Climate Change Science Program [CCSP] 2008, pp. 5-31, 5-32). The
long-term record at Key West shows that sea level rose on average 0.088
inches (0.224 cm) annually between 1913 and 2006 (National
Oceanographic and Atmospheric Administration [NOAA] 2008, p. 1). This
equates to approximately 8.76 inches (22.3 cm) in 100 years (NOAA 2008,
p. 1).
In a technical paper following its 2007 report, the IPCC (2008, p.
28) emphasized it is very likely that the average rate of sea level
rise during the 21st century will exceed that from 1961 to 2003,
although it was projected to have substantial geographical variability.
Partial loss of the Greenland and Antarctic ice sheets could result in
many feet (several meters) of sea level rise, major changes in
coastlines, and inundation of low-lying areas (IPCC 2008, pp. 28-29).
Low-lying islands and river deltas will incur the largest impacts (IPCC
2008, pp. 28-29). According to CCSP (2008, p. 5-31), much of low-lying,
coastal south Florida ``will be underwater or inundated with salt water
in the coming century.'' This means that most occupied, suitable, and
potential habitat for Miami blue will likely be either submerged or
affected by increased flooding.
The 2007 IPCC report found a 90 percent probability of an
additional 7 to 23 inches and possibly as high as many feet (several
meters) of sea level rise by 2100 in the Keys. This would cause major
changes to coastlines and inundation of low-lying areas like the Keys
(IPCC 2008, pp. 28-29). The IPCC (2008, pp. 3, 103) concluded that
climate change is likely to increase the occurrence of saltwater
intrusion as sea level rises. Since the 1930s, increased salinity of
coastal waters contributed to the decline of cabbage palm forests in
southwest Florida (Williams et al. 1999, pp. 2056-2059), expansion of
mangroves into adjacent marshes in the Everglades (Ross et al. 2000,
pp. 9, 12-13), and loss of pine rockland in the Keys (Ross et al. 1994,
pp. 144, 151-155).
Hydrology has a strong influence on plant distribution in these and
other coastal areas (IPCC 2008, p. 57). Such communities typically
grade from salt to brackish to freshwater species. In the Keys,
elevation differences between such communities are very slight (Ross et
al. 1994, p. 146), and horizontal distances are also small. Human
developments will also likely be significant factors influencing
whether natural communities can move and persist (IPCC 2008, p. 57;
CCSP 2008, p. 7-6). For the Miami blue, this means that much of the
butterfly's habitat in the Keys, as well as habitat in other parts of
its historical range, will likely change as vegetation changes. Any
deleterious changes to important host plants and nectar sources could
further diminish the likelihood of the subspecies' survival and
recovery.
The Nature Conservancy (TNC) (2010, p. 1) used Light Detection and
Ranging (LIDAR) remote sensing technology to derive digital elevation
models and predict future shorelines and distribution of habitat types
for Big Pine Key based on sea level rise predictions ranging from the
best case to worst case scenarios described by current scientific
literature. In the Keys, models predicted that sea level rise will
first result in the conversion of habitat and eventually the complete
inundation of habitat. In the best case scenario, a rise of 7 inches
(18 cm) would result in the inundation of 1,840 acres (745 ha) (34
percent) of Big Pine Key and the loss of 11 percent of the island's
upland habitat (TNC 2010, p. 1). In the worst case scenario, a rise of
4.6 feet (140 cm) would result in the inundation of about 5,950 acres
(2,409 ha) (96 percent) and the loss of all upland habitat (TNC 2010,
p. 1). Although the Miami blue no longer occurs on Big Pine Key, it was
historically found on this island. If modeling is accurate, under the
worst case scenario, even upland habitat on Big Pine Key will become
submerged, thereby making the butterfly's potential recolonization or
survival at this and other low-lying locations in the Keys very
unlikely.
Similarly, using a spatially explicit model for the Keys, Ross et
al. (2009, p. 473) found that mangrove habitats will expand steadily at
the expense of upland and traditional habitats as sea level rises. Most
of the upland and transitional habitat in the central portion of
Sugarloaf Key is projected to be lost with a 0.2-meter rise (0.7-foot
rise) in sea level; a 0.5-meter rise (1.6-foot rise) in sea level can
result in a 95 percent loss of upland habitat by 2100 (Ross et al.
2009, p. 473). Furthermore, Ross et al. (2009, pp. 471-478) suggested
that interactions between sea level rise and pulse disturbances (e.g.,
storm surges or fire [see Factor E]) can cause vegetation to change
sooner than projected based on sea level alone.
Scientific evidence that has emerged since the publication of the
IPCC Report (2007) indicates an acceleration in global climate change.
Important aspects of climate change seem to have been underestimated
previously, and the resulting impacts are being felt sooner. For
example, early signs of change suggest that the 1[deg]C of global
warming the world has experienced to date may have already triggered
the first tipping point of the Earth's climate system--the
disappearance of summer Arctic sea ice. This process could lead to
rapid and abrupt climate change, rather than the
[[Page 49553]]
gradual changes that were forecasted. Other processes to be affected by
projected warming include temperatures, rainfall (amount, seasonal
timing, and distribution), and storms (frequency and intensity) (see
Factor E). The MIT scenarios combine various levels of sea level rise,
temperature change, and precipitation differences with population,
policy assumptions, and conservation funding changes. All of the
scenarios, from small climate change shifts to major changes, will have
significant effects on the Keys.
We have identified a number of threats to the habitat of the Miami
blue which have operated in the past, are impacting the subspecies now,
and will continue to impact the subspecies in the foreseeable future.
Based on our analysis of the best available information, we find that
the present and threatened destruction, modification, or curtailment of
the subspecies' habitat is a threat to the subspecies throughout all of
its range. We have no reason to believe that this threat will change in
the foreseeable future. The decline of butterflies in south Florida is
primarily the result of the long-lasting effects of habitat loss,
degradation, and modification from human population growth and
associated development and agriculture. Environmental effects resulting
from climatic change, including sea level rise, are expected to become
severe in the future and result in additional losses. Although efforts
have been made to restore habitat in some areas, the long-term effects
of large-scale and wide-ranging habitat modification, destruction, and
curtailment will last into the foreseeable future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Collection
Rare butterflies and moths are highly prized by collectors, and an
international trade exists in specimens for both live and decorative
markets, as well as the specialist trade that supplies hobbyists,
collectors, and researchers (Collins and Morris 1985, pp. 155-179;
Morris et al. 1991, pp. 332-334; Williams 1996, pp. 30-37). The
specialist trade differs from both the live and decorative market in
that it concentrates on rare and threatened species (U.S. Department of
Justice [USDJ] 1993, pp. 1-3; United States v. Skalski et al., Case No.
CR9320137, U.S. District Court for the Northern District of California
[USDC] 1993, pp. 1-86). In general, the rarer the species, the more
valuable it is; prices can exceed $25,000 for exceedingly rare
specimens. For example, during a 4-year investigation, special agents
of the Service's Office of Law Enforcement executed warrants and seized
over 30,000 endangered and protected butterflies and beetles, with a
total wholesale commercial market value of about $90,000 in the United
States (USDJ 1995, pp. 1-4). In another case, special agents found at
least 13 species protected under the Act, and another 130 species
illegally taken from lands administered by the Department of the
Interior and other State lands (USDC 1993, pp. 1-86; Service 1995, pp.
1-2). Law enforcement agents routinely see butterfly species protected
under the Convention on International Trade in Endangered Species of
Wild Fauna and Flora (CITES) during port inspections in Florida, often
without import declarations or the required CITES permits (E.
McKissick, Service Law Enforcement, pers. comm. 2011).
Several listings of butterflies as endangered or threatened species
under the Act have been based, at least partially, on intense
collection pressure. Notably, the Saint Francis' satyr (Neonympha
mitchellii francisci) was emergency-listed as endangered on April 15,
1994 (59 FR 18324). The Saint Francis' satyr was demonstrated to have
been significantly impacted by collectors in just a 3-year period (59
FR 18324). The Callippe and Behren's silverspot butterflies (Speyeria
callippe callippe and Speyeria zerene behrensii) were listed as
endangered on December 5, 1997 (62 FR 64306), partially due to
overcollection. The Blackburn's sphinx moth (Manduca blackburni) was
listed as endangered on February 1, 2000 (65 FR 4770), partially due to
overcollection by private and commercial collectors. The Schaus
swallowtail (Heraclides [Papilio] aristodemus ponceanus), the only
federally listed butterfly in Florida, was reclassified from threatened
to endangered in 1984 due to its continued decline (49 FR 3450). At the
time of its original listing, some believed that collection represented
a threat. As the Schaus decreased in distribution and abundance,
collection was believed to be a greater threat than at the time of
listing (49 FR 3450).
Collection was cited as a threat to the Miami blue in both the
original and subsequent petitions for emergency listing. The State's
management plan for the Miami blue acknowledges that butterfly
collecting may stress small, localized populations and lead to the loss
of individuals and genetic variability, but also indicates that there
is no evidence or information on current or past collection pressure on
the Miami blue (FWC 2010, p. 13). Butterflies in small populations are
vulnerable to harm from collection (Gall 1984, p. 133). A population
may be reduced to below sustainable numbers (Allee effect) by removal
of females, reducing the probability that new colonies will be founded.
Collectors can pose threats to butterflies because they may be unable
to recognize when they are depleting colonies below the thresholds of
survival or recovery (Collins and Morris 1985, pp. 162-165). There is
ample evidence of collectors impacting other imperiled and endangered
butterflies (Gochfeld and Burger 1997, pp. 208-209), host plants (Cech
and Tudor 2005, p. 55), and even contributing to extirpations (Duffey
1968, p. 94). For example, the federally endangered Mitchell's satyr
(Neonympha mitchellii mitchellii) is believed to have been extirpated
from New Jersey due to overcollecting (57 FR 21567; Gochfeld and Burger
1997, p. 209).
Although we do not have evidence of illegal collection of the Miami
blue, we do have evidence of illegal collection of other butterflies
from Federal lands in south Florida, including the endangered Schaus
swallowtail. In a 1993 case, three defendants were indicted for
conspiracy to violate the wildlife laws of the United States, including
the Endangered Species Act, the Lacey Act, and 18 U.S.C. 371 (USDC
1993, p. 1). Violations involved numerous listed, imperiled, and common
species from many locales; defendants later pled guilty to the felonies
(Service 1995, p. 1). As part of the evidence cited in the case,
defendants exchanged butterflies taken from County and Federal lands in
Florida and acknowledged that it was best to trade ``under the table''
to avoid permits and ``extra red tape'' because some were on the
endangered species list (USDC 1993, p. 9). Acknowledging the
difficulties in obtaining Schaus swallowtail, defendants indicated that
they would traffic amongst each other to exchange a Schaus for other
extremely rare butterflies (USDC 1993, p. 10). These defendants engaged
in interstate commerce, exchanging a male Schaus in 1984 in the course
of a commercial activity (USDC 1993, p. 11). One defendant also
trafficked with a collector in Florida, dealing the federally listed
San Bruno elfin butterfly (Callophrys mossii bayensis) (USDC 1993, p.
67).
Illegal collection of butterflies on State, Federal, and other
lands in Florida appears ongoing, prevalent, and damaging. As part of
the aforementioned case, one defendant, who admitted getting caught
collecting within ENP and Loxahatchee National Wildlife Refuge, stated
that he ``got
[[Page 49554]]
away with it each time, simply claiming ignorance of the laws * * *.''
(USDC 1993, p. 13). Another defendant detailed his poaching in Florida
and acquisition of federally endangered butterflies, acknowledging that
he had ``fared very well, going specifically after rare stuff'' (USDC
1993, pp. 28-29). The same defendant offered to traffic atala
hairstreaks (Eumaeus atala), noting that he did not do very well and
had only taken about 600 bugs in 9 days and that this number seemed
poor for Florida (USDC, p. 46). He further stated that collecting had
become difficult in Florida due to restrictions and extreme loss of
habitat, admitting that he needed to poach rare butterflies from
protected parks (USDC 1993, p. 45). Methods to poach wildlife and means
to evade wildlife regulations, laws, and law enforcement were given
(USDC 1993, p. 33). In a separate incident in 2008, an individual was
observed attempting to take butterflies from Service lands in the Keys
(D. Pharo, Service Law Enforcement, pers. comm. 2008). When confronted
by a FWC officer, he lied about his activities; a live swallowtail
butterfly (unidentified) was found in an envelope on his person, a
collapsible butterfly net was found in a nearby area, and a cooler
containing other live butterfly species was in his car (D. Pharo, pers.
comm. 2008).
Additionally, we are aware of and have documented evidence of
interest in the collection of other imperiled butterflies in south
Florida. In the aforementioned indictment, one defendant noted that
there was a ``huge demand for Florida stuff,'' that he knew ``exactly
where all the rare stuff is found,'' that he ``can readily get
material,'' and that in most cases he would ``have to poach the
material from protected parks'' (USDC 1993, p. 44). Salvato (pers.
comm. 2011e) has also been contacted by several individuals requesting
specimens of two Federal candidates, the Florida leafwing (Anaea
troglodyta floridalis) and Bartram's hairstreak (Strymon acis
bartrami), or seeking information regarding locations where they may be
collected in the field. In addition, interest in the collection of the
Florida leafwing was posted by two parties on at least one Web site in
2010 along with advice on where and how to bait trap, despite the fact
that this butterfly mainly occurs on Federal lands within ENP. Thus,
there is established and ongoing collection pressure for rare
butterflies, including two other highly imperiled candidate species in
south Florida.
We are also aware of multiple Web sites that offer specimens of
south Florida's candidate butterflies for sale (M. Minno, pers. comm.
2009; C. Nagano, Service, pers. comm. 2011). At one Web site, male and
female Florida leafwing specimens can be purchased for [euro]110.00 and
[euro]60.00 (euros), respectively (approximately $153.18 and $83.55).
It is unclear from where the specimens originated or when these were
collected, but this butterfly is now mainly restricted to ENP. The same
Web site offers specimens of Bartram's hairstreak for [euro]10.00
($13.93). Although the specifics on its collection are not clear, this
butterfly now mainly occurs on protected Federal, State, and County
lands. The same Web site offers specimens of two other butterflies
similar in appearance to the Miami blue; the ceraunus blue currently
sells for [euro]4.00 ($5.57), and the cassius blue is available for
[euro]2.50-10.00 ($3.48-$13.93). Additionally, other subspecies of
Cyclargus thomasi that occur in foreign countries are also for sale. It
is clear that a market currently exists for both imperiled species and
those similar in appearance to the Miami blue.
The potential for unauthorized or illegal collection of the Miami
blue (eggs, larvae, pupae, or adults) exists, despite its State-
threatened status and the protections provided on Federal (and State)
land. Illegal collection could occur without detection at remote
islands of KWNWR since these areas are difficult to patrol. The
localized distribution and small population size render this butterfly
highly vulnerable to impacts from collection. At this time, removal of
any individuals may have devastating consequences to the survival of
the subspecies. Although the Miami blue is no longer believed to be
present at BHSP, its return is possible. At BHSP, the butterfly, like
other wildlife and plant species within the Florida park system, is
protected from unauthorized collection (Chapter 62 D-2.013(5)) (see
Factor D). However, because BHSP is so heavily used, continual
monitoring for illegal collections is a challenge. Daniels (pers. comm.
2002a) believed that additional patrols would be helpful because
unauthorized collection of specimens is possible, even though
collection is prohibited (J. Daniels, pers. comm. 2002a). In addition,
any colonies that might be found or become established outside of BHSP
or other protected sites would also not be patrolled and would be at
risk of collection.
Although the Miami blue's status as a State-threatened species
provides some protection, this protection does not include provisions
for other species of blues that are similar in appearance. Therefore,
it is quite possible that collectors authorized to collect similar
species may inadvertently (or purposefully) collect the Miami blue
butterfly thinking it was, or planning to claim they thought it was,
the cassius blue, nickerbean blue, or ceraunus blue, which also occur
in the same general geographical area and habitat type. Federal listing
of other similar butterflies can partially reduce this threat (see
Similarity of Appearance below) and provide added protective measures
for the Miami blue above those afforded by the State.
In summary, due to the few metapopulations, small population size,
restricted range, and remoteness of occupied habitat, we believe that
collection is a significant threat to the subspecies and could
potentially occur at any time. Even limited collection from the small
population in KWNWR (or other populations, if discovered) could have
deleterious effects on reproductive and genetic viability and thus
could contribute to its extinction.
Scientific Research and Conservation Efforts
Some techniques (e.g., capture, handling) used to understand or
monitor the Miami blue have the potential to cause harm to individuals
or habitat. Visual surveys, transect counts, and netting for
identification purposes have been performed during scientific research
and conservation efforts with the potential to disturb or injure
individuals or damage habitat. Mark-recapture, a common method used to
determine population size, has been used by some researchers to monitor
Miami blue populations. This method has received some criticism. While
mark-recapture may be preferable to other sampling estimates (e.g.,
count-based transects) in obtaining demographic data when used in a
proper design on appropriate species, such techniques may also result
in deleterious impacts to captured butterflies (Mallet et al. 1987, pp.
377-386; Murphy 1988, pp. 236-239; Haddad et al. 2008, pp. 929-940).
Although effects may vary depending upon taxon, technique, or other
factors, some studies suggest that marking may damage or kill
butterflies or alter their behaviors (Mallet et al. 1987, pp. 377-386;
Murphy 1988, pp. 236-239). Murphy (1988, p. 236) and Mattoni et al.
(2001, p. 198) indicated that studies on various lycaenids have
demonstrated mortality and altered behavior as a result of marking.
Conversely, other studies have found that marking did not harm
individual butterflies or populations (Gall 1984, pp. 139-154; Orive
and Baughman 1989, p. 246; Haddad et al. 2008, p. 938). No studies
[[Page 49555]]
have been conducted to determine the potential effects of marking on
the Miami blue. Although data are lacking, researchers permitted to use
such techniques have been confident in their abilities to employ the
techniques safely with minimal effect on individuals handled.
Researchers currently studying the population within KWNWR have opted
to not use mark-release-recapture techniques due to the potential for
damage to this small, fragile butterfly (N. Haddad, pers. comm. 2011).
Captive propagation and reintroduction activities may present risks
if wild populations are impacted or if the species is introduced to new
or inappropriate areas outside of its historical range (65 FR 56916-
56922). Although butterflies were successfully reared in captivity at
the UF with the support of State and Federal agencies, efforts to
reintroduce the Miami blue to portions of its historical range did not
result in the establishment of any new populations (Emmel and Daniels
2009, pp. 4-5; FWC 2010, p. 8). While some monitoring occurred
following releases, it is not clear why captive-reared individuals did
not persist in the wild. Perhaps experiments using surrogate species
(e.g., other lycaenids) and more structured and intense monitoring
following releases can help elucidate possible causes for failure and
improve chances for reestablishment in the future.
Declines in the captive colony in 2005 and 2006 were attributed to
a baculovirus; consequently, this captive colony was terminated after
30 generations and another was started with new stock from BHSP
(Saarinen 2009, p. 92). Baculovirus infections are capable of
devastating both laboratory and wild butterfly populations (Saarinen
2009, pp. 99, 119). Irrevocable consequences may occur if a pathogen is
transferred from laboratory-reared to wild populations. Genetic
diversity within the captive colony was lost over time (between
generations) (Saarinen 2009, p. 100). At one point, the captive colony
was not infused with new genetic material for approximately 1 year due
to low numbers within the wild population; decreases in genetic
diversity, allelic richness, and number of individuals produced
occurred during this time (Saarinen 2009, p. 100). While captive
propagation and reintroduction efforts offer enormous conservation
potential, there can be associated risks and ramifications to both wild
and captive-reared individuals and populations.
The use of captive-reared Miami blues in pesticide-use and life-
history studies can be questioned and has been criticized by some (FWC
2010, p. 10). All experiments were conducted with captive-reared
individuals; no wild individuals were used. Individuals used in
experiments were not intended for release back into the wild or were
reared specifically for this purpose. Researchers involved with the
captive colony and others conducting scientific studies or other
conservation efforts were authorized by appropriate agencies to conduct
such work.
In summary, we believe that captive propagation and reintroduction
may be important components of the subspecies' survival and recovery,
but such actions need to be carefully planned, implemented, and
monitored. Any future efforts should only be initiated after it has
been determined that: Such actions will not harm the wild population,
rigorous standards are met, and commitments are in place to increase
the likelihood of success and maximize knowledge gained.
On the basis of this analysis, we find that overutilization for
commercial, recreational, scientific, or educational purposes is a
threat to the Miami blue. Collection is a significant threat to the
subspecies. Based on our analysis of the best available information, we
have no reason to believe that its vulnerability to collection and
risks associated with scientific or conservation efforts will change in
the foreseeable future.
C. Disease or predation
The effects of disease or predation are not well known. Because the
Miami blue is known from only a few locations and population size
appears low, disease and predation could pose a threat to its survival.
Disease
A baculovirus was confirmed within the captive colony, and
infection caused the death of Miami blue larvae in captivity (see
Factor B above) (Saarinen 2009, p. 120). Pathogens have affected other
insect captive-breeding programs, however, this was the first time a
baculovirus was found to affect a captive colony of an endangered
Lepidopteran (Saarinen 2009, p. 120). A baculovirus or other disease or
pathogens have the potential to destroy wild populations (Saarinen
2009, p. 99). Plant pathogens could also negatively impact host plant
survival, host growth, or the production of terminal host growth
available to developing larvae (Emmel and Daniels 2004, p. 14). At this
time, we are not aware of any disease or pathogens affecting Miami blue
butterflies or host plants in the wild.
Predation
Predation of adults or immature stages was not observed during
monitoring at BHSP, despite the presence of potential predators (Emmel
and Daniels 2004, p. 12; Trager 2009, p. 152). Several species of
social wasps, specifically paper wasps (Polistes) and yellow jackets
(Vespula), are known to depredate Lepidoptera on nickerbean and
surrounding vegetation at BHSP and other sites with suitable habitat,
but predation on Miami blue larvae was not observed (Trager 2009, p.
152). Carroll and Loye (2006, p. 18) encountered a parasitic wasp,
Lisseurytomella flava, during their studies of the balloonvine insects
on northern Key Largo during the late 1980s. No wasp parasitism towards
Miami blue larvae was noted (Carroll and Loye 2006, p. 24). However,
this wasp, along with the Miami blue, was absent from continued
balloonvine sampling in 2003, suggesting the wasp may have used the
butterfly as host.
Cannon et al. (2007, p. 16) observed wasps (unidentified) eating
Miami blue larvae at KWNWR; wasps and dragonflies were also observed to
chase adults in flight. Adult Miami blues were found entrapped in the
webs of silver orb spiders (Argiope argentata) (Cannon et al. 2007, p.
16). Trager (2009, pp. 149, 153-154) indicated that the Miami blue is
likely depredated under natural conditions, but only predation by an
adult brown anole lizard (Anolis sagrei) was observed during field
studies. Iguanas likely consume eggs and pupae when opportunistically
feeding (P. Hughes, pers. comm. 2009; Daniels 2009, p. 5; FWC 2010, p.
13), especially since the butterfly uses the same terminal growth of
host plants (see Factor E). Predators and parasitoids have been
suggested as potential contributors to the butterfly's decline (M.
Minno, pers. comm. 2010), but this has not been observed or confirmed
in the field (Trager 2009, p. 149; Minno and Minno 2009, p. 78; FWC
2010, pp. 13, 24).
Overall, the extent to which native or exotic ants and other
predators and parasitoids may pose a threat to the Miami blue is not
clear, but deserves further attention. For example, invasive fire ants
(Solenopsis invicta) were first confirmed in counties within the
historical range of the Miami blue as early as 1958 (Hillsborough);
other counties were confirmed in the late 1960s (Brevard and Volusia)
and 1970s (Broward, Collier, Miami-Dade, Lee, Monroe) (Callcott and
Collins 1996, p. 249); infestation has since expanded. In addition to
the possible direct effects of predation, fire ants can also disrupt
[[Page 49556]]
arthropod communities and displace native ants. For example, in one
study, Porter and Savignano (1990, pp. 2095-2106) found that S. invicta
reduced species richness by 70 percent and abundance of native ants by
90 percent.
Both the red imported fire ant and the little fire ant (Wasmannia
auropunctata), another invasive exotic ant, currently occur at BHSP
(Saarinen and Daniels 2006, p. 71). In one study in Key Largo, fire
ants were found within half of the study transects and in close
proximity to the edge of hardwood hammock habitat (Forys et al. 2001,
p. 257). Forys et al. (2001, p. 257) found all immature swallowtail
life stages to be vulnerable to predation by imported fire ants and
recognized the potential impact of this predatory insect on the
federally endangered Schaus swallowtail and other butterflies in south
Florida. Thus, immature life stages of the Miami blue may be vulnerable
to predation by fire ants within its current locations or if the
butterfly still persists, elsewhere in its historical range.
In a greenhouse situation, Trager (2009, p. 151) observed fire ants
removing Miami blue eggs in an indoor flight cage, but noted that the
ants did not attack larvae on the same plant. In his studies, a captive
colony of fire ants was found to consume captive-reared Miami blue
pupae in food trays; however, the ants did not remove newly laid eggs
from the host plant and even exhibited weak tending behavior toward
larvae (Trager 2009, pp. 151-152). At this time, it is unclear to what
extent native and exotic predatory insects may be impacting wild Miami
blue populations.
Some ant species may also protect Miami blue larvae against
parasitoids and predators; however, this has not yet been observed in
the wild (Trager and Daniels 2009, 479; Trager 2009, p. 101). In
laboratory studies, Camponotus floridanus ants have been shown to
display strong defensive behaviors (e.g., rapidly circling larvae,
recruiting nearby workers, and lunging at forceps) when disturbed
(Trager and Daniels 2009, p. 480; Trager 2009, p. 102). The large size
of this ant species and nearly constant tending may serve as a visual
deterrent to potential attackers; however, researchers acknowledged
that they have no definitive evidence that C. floridanus are more
effective defenders of Miami blue larvae than small-bodied ant species
(Trager and Daniels 2009, p. 480; Trager 2009, p. 97).
Researchers have suggested that some ant species may depredate
Miami blue larvae or may opportunistically tend larvae without
providing protection against predators or other benefits (Saarinen and
Daniels 2006, p. 73; Saarinen 2009, pp. 134, 138). However, Trager and
Daniels (2009, pp. 478-481) recorded a universal tending response among
ants consistent with a mutualistic interaction through both field
observations and laboratory trials. They did not observe any
depredation of larvae by ants in the field and, based upon
observations, doubted that many ant species regularly depredate larvae
(Trager and Daniels 2009, pp. 479-481; Trager 2009, p. 149).
Studies suggest that various stressors (e.g., baculovirus, fire
ants) have the potential to negatively impact the Miami blue, but we do
not have evidence of their impacts to wild populations. The Miami blue
may have some mechanisms to potentially deter predators and
parasitoids, but these are not well understood. Disease and predation
have the potential to impact the Miami blue's continued survival, given
its few remaining populations, low abundance, and limited range. Based
on our analysis of the best available information, we do not believe
that disease or predation is a significant threat to its overall status
at this time. However, given its small population size, disease and
predation have the potential to impact the subspecies now or in the
foreseeable future.
D. The Inadequacy of Existing Regulatory Mechanisms
Despite the fact that they contain several protections for the
Miami blue, Federal, State, and local laws have not been sufficient to
prevent past and ongoing impacts to the Miami blue and its habitat
within its current and historical range.
In response to a petition from the NABA in 2002, the FWC emergency-
listed the Miami blue butterfly in 2002, temporarily protecting the
butterfly. On November 19, 2003, the FWC declared the Miami blue
butterfly endangered (68A-27.003), making its protection permanent. On
November 8, 2010, the FWC adopted a revised listing classification
system, moving from a multi-tiered to single-category system. As a
consequence of this change, the Miami blue butterfly (along with other
species) became a State-threatened species; its original protective
measures remained in place (68A-27.003, amended). This designation
prohibits any person from taking, harming, harassing, possessing,
selling, or transporting any Miami blue or parts thereof or eggs,
larvae or pupae, except as authorized by permit from the executive
director, with permits issued based upon whether issuance would further
management plan goals and objectives. Although these provisions
prohibit take of individuals, there is no substantive protection of
Miami blue habitat or protection of potentially suitable habitat.
Therefore, while the Miami blue butterfly is afforded some protection
by its presence on Federal (and State) lands, losses of suitable and
potential habitat outside of these areas are expected to continue (see
Factor A).
The Miami blue's presence on Federal (and State) lands offers some
insulation against collection, but protection is somewhat limited (see
Factor B). In addition, the State's protection of the Miami blue does
not extend to butterflies that are similar in appearance (see
Similarity of Appearance below). Since there are only slight
morphological differences between the Miami blue and other butterfly
species in the same areas, the Miami blue remains at-risk to illegal
collection, despite the regulatory mechanisms already in place (see
Factor B).
As part of its listing process, the FWC has completed a biological
status review and management plan for the subspecies (FWC 2003, pp. 1-
26). This management plan was recently revised (FWC 2010, pp. ii-39).
Although the management plan is a fundamental step in outlining
conservation needs, it may be insufficient for achieving conservation
goals and long-term persistence. Recommended conservation strategies
and actions within the plan are voluntary and dependent upon adequate
funding, staffing, and the cooperation and participation of multiple
agencies and private entities, which may or may not be available or
able to assist. Conservation strategies include suggested actions to
maintain, protect, and monitor known metapopulations; establish new
metapopulations; and conduct additional research to support
conservation (FWC 2010, pp. 17-26).
As a Federal candidate subspecies, the Miami blue is afforded some
protection through sections 7 and 10 of the Act and associated policies
and guidelines, but protection is limited. Federal action agencies are
to consider the potential effects to the butterfly and its habitat
during the consultation process. Applicants and action agencies are
encouraged to consider candidate species when seeking incidental take
for other listed species and when developing habitat conservation
plans. On Federal lands, such as KWNWR, candidate species are treated
as ``proposed threatened.''
Although the Miami blue occurs on Federal (and possibly State) land
that offers protection, these areas are vast
[[Page 49557]]
and often heavily used. Signage prohibiting collection is sometimes
lacking; patrolling and monitoring of activities can be limited and
dependent upon the availability of staffing and resources. Within
KWNWR, the Marquesas Keys are open to the public; portions of the beach
on Boca Grande are closed to the public (T. Wilmers, pers. comm.
2011b). In general, occupied islands are remote and difficult to
patrol, and illegal use still occurs (see Factor E). Therefore, the
potential for illegal collection and damage to sensitive habitats still
exists (see Factors B and E).
Prior to its apparent extirpation, the metapopulation at BHSP was
afforded some protection by its presence on State lands. All property
and resources owned by FDEP are generally protected from harm in
Chapter 62D-2.013(2) and animals are specifically protected from
unauthorized collection in Chapter 62D-2.013(5) of the Florida
Statutes. Exceptions are made for collecting permits, which are issued,
``for scientific or educational purposes.'' Still, protection of
resources at BHSP is a challenge due to the park's popularity and high
use (See Factor E). However, in 2010, the FDEP hired a temporary, full-
time biologist to work on Miami blue conservation issues at BHSP,
including patrol of sensitive habitats.
Permits are required from the FWC for scientific research on and
collection of the Miami blue. For work on Federal lands (i.e., KWNWR,
ENP, and BNP), permits are required from the Service or the NPS. For
work on State lands, permits are required from FDEP. Permits are also
required for work on County-owned lands.
Despite these existing regulatory mechanisms, the Miami blue
continues to decline due to the effects of habitat loss (see Factor A)
and a wide array of other factors (see Factors B and E). We find that
regulatory measures have been insufficient to significantly reduce or
remove the threats to the Miami blue and, therefore, that the
inadequacy of existing regulatory mechanisms is a threat to the
subspecies throughout all of its range. Based on our analysis of the
best available information, we have no reason to believe that the
aforementioned regulations, which currently do not offer adequate
protection to the Miami blue, will be improved in the foreseeable
future.
E. Other Natural or Manmade Factors Affecting its Continued Existence
Impacts From Iguanas
The exotic green iguana (Iguana iguana) is a severe threat to the
Miami blue (75 FR 69258; Daniels 2009, p. 5; FWC 2010, pp. 6, 13; Olle
2010, pp. 4, 14). Iguanas are prevalent within the Keys, and sightings
within occupied and potential habitat are common (P. Cannon, pers.
comm. 2009, 2010d, 2010e). Effects of herbivory to the host plant
(nickerbean) at BHSP were evident by late 2008 and early 2009 (Emmel
and Daniels 2009, p. 4; Daniels 2009, p. 5; P. Hughes, pers. comm.
2009; P. Cannon, pers. comm. 2009; A. Edwards, pers. comm. 2009). In
January 2009, Cannon (pers. comm. 2009) reported that iguanas had
stripped all new nickerbean growth, causing substantial losses since
November 2008. In April 2009, nickerbean showed signs of limited growth
due to chronic herbivory (P. Hughes, pers. comm. 2009).
In addition to damage, iguanas likely consume eggs and pupae when
opportunistically feeding (P. Hughes, pers. comm. 2009; Daniels 2009,
p. 5; FWC 2010, p. 13), especially since the butterfly uses the same
terminal growth of host plants. For many years, host plant abundance
within BHSP appeared capable of sustaining both iguanas and Miami
blues. Depressed numbers of Miami blues in 2008, however, were likely
the result of both a severe drought and impacts to the nickerbean from
iguanas feeding on the terminal nickerbean growth (FWC 2010, p. 6).
During the winter of 2010, prolonged and unseasonably cold temperatures
in the lower Keys resulted in a considerable decline in available
nickerbean at BHSP (Olle 2010, p. 14). The suppressed population of the
Miami blue at this site during this time may not have been able to
survive this temporary, but severe, reduction in nickerbean, likely
caused by the combined influences of iguanas and environmental factors
(e.g., drought and cold).
Iguana tracks were found on islands occupied by the Miami blue in
KWNWR (Cannon et al. 2007, p. 16; T. Wilmers, pers. comm. 2011c). Three
large, gravid female iguanas were trapped and removed from the
Marquesas in February 2011 (T. Wilmers, pers. comm. 2011d). To date,
the presence of iguanas has been documented on four islands (two
islands within the Marquesas, and Boca Grande and Woman Key) (T.
Wilmers, pers. comm. 2011a). Cannon et al. (2007, p. 16) stated that
the exotic herbivore has the potential to impact host and nectar
plants. Iguanas have also been observed on three islands in GWHNWR
(Snipe Point, Sawyer Key, and Secret Key) since 2006 (T. Wilmers, pers.
comm. 2011b).
Resource agencies are working to combat the threat of green iguanas
in areas occupied (and recently occupied) by the Miami blue. At BHSP,
cooperative efforts have resulted in the trapping and removal of 130
iguanas between November 2009 and June 2011 (Emmel and Daniels 2009, p.
4; FWC 2010, p. 17; E. Kiefer, pers. comm. 2011a, 2011b). While removal
efforts have significantly decreased the number of iguanas within BHSP,
these management actions will need to be an ongoing effort due to the
prevalence of iguanas in the surrounding areas (R. Zambrano, pers.
comm. 2009). Efforts are also underway to address this threat at KWNWR
(T. Wilmers, pers. comm. 2011a, 2011c, 2011d, 2011e). Despite
cooperative efforts, the threat from iguanas is expected to continue
due to their widespread distribution and the difficulties in control.
Competition
Host resource competition from other butterfly species could
deleteriously impact metapopulation productivity of the Miami blue. The
introduction of or future island colonization by potential Lepidopteran
competitors may impact the Miami blue metapopulation. The nickerbean
blue, cassius blue, and Martial's scrub hairstreak are known to use
various species of nickerbean host plants throughout their range
(Glassberg et al. 2000, pp. 74-80; Calhoun et al. 2002, p. 15). The
nickerbean blue and Martial's scrub hairstreak have been documented
using gray nickerbean as a host plant at BHSP (Daniels et al. 2005, p.
174; P. Cannon, pers. comm. 2010g). Such host use may represent direct
competition for host resources (Emmel and Daniels 2004, p. 14).
However, Calhoun et al. (2002, p. 18) believed it was unlikely that
competition played a significant role in the decline of the Miami blue
based on the abundance of host plant sources available to lycaenids
throughout the Lower Keys. We do not have evidence to suggest that host
resource competition is a threat to the Miami blue at this time or is
likely to become so in the future.
Inadvertent Impacts From Humans
Inadvertent damage from humans can affect the Miami blue and its
habitat in its current and former range. For example, the seed pods of
balloonvine ``pop'' when squeezed and can be targeted by humans. Damage
to balloonvine has been documented along roads in the Keys (J. Loye,
University of California-Davis, pers. comm. 2003a, 2003b). During a
study in the mid 1980s examining balloonvine and its associated insect
community, Loye (pers. comm. 2003a) found a difference in insect
diversity between sites along
[[Page 49558]]
roads and those without road access. Acknowledging other possible
contributing factors (e.g., mosquito control, car emissions), Loye
(pers. comm. 2003a) indicated that collectors and maintenance crews
damaged balloons near roads, stating that ``humans damaged every
balloon that could be easily found at our study sites'' (J. Loye, pers.
comm 2003b). It is not clear what, if any, impact this had on the
butterfly at or since that time. However, damage to host plants (whole
or parts) could contribute to mortality of eggs or larvae.
BHSP is heavily used by the public for recreational purposes, and
although the butterfly has not been seen at this location since early
2010, suitable habitat is located along trails and other high-use areas
(e.g., campgrounds). Former colonies may have experienced disturbance
from Park visitors. Trampling of host plants and well-worn footpaths
were evident, at least periodically from 2002 to 2010, and during times
when other stressors (e.g., cold, drought, iguanas) occurred (P.
Halupa, pers. obs. 2002; D. Olle, pers. comm. 2010; M. Salvato, pers.
comm. 2010a; R. Zambrano, pers. comm. 2010). To protect larval host
plants and adult nectar sources, the Florida Park Service (FPS) erected
fencing and signage around the majority of the south colony site at
BHSP. Although this is expected to minimize damage to the largest
habitat patch, other small habitat patches (as small as 15.0 by 15.0
feet [4.6 by 4.6 meters]) elsewhere on the island are still vulnerable
to intentional or accidental damage. Fencing small colony sites or
patches of available habitat is impractical and would make exact
locations of colonies more evident, possibly increasing the risk of
illegal collection or harm should the Miami blue return to the island.
KWNWR lacks human developments, but local disturbances result from
illicit camping, fire pits, smugglers, vandals, and immigrant landings.
These disturbances are generally infrequent for most islands within
KWNWR with the exception of Boca Grande, which contains the largest
amounts of beach. Recreational visitation is high on Boca Grande,
particularly during weekends (Cannon et al. 2010, p. 852). Trampling of
dune vegetation has been a long-term problem on Boca Grande, and fire
pits have been found many times over the past two decades on both Boca
Grande and the Marquesas Keys (Cannon et al. 2010, p. 852). In
addition, the large amount of dead vegetation intermingled with host
plants on Boca Grande and the Marquesas Keys makes the threat of fire
(natural or human-induced), a significant threat to the Miami blue
(Cannon et al. 2007, p. 13; 2010, p. 852). Immature stages (eggs,
larvae), which are sedentary, would be particularly vulnerable.
Glassberg and Olle (2010, p. 1) asserted that ``the proximity of the
islands within KWNWR, to both Key West and the Dry Tortugas, invite
human mischief, and largely go unpoliced.'' These areas within KWNWR
are remote and accessible mainly by boat, making them difficult to
patrol and monitor.
In summary, inadvertent impacts from humans may have affected the
Miami blue and its habitat. Due to the location of occupied and
suitable habitat, the popularity of these areas with humans, and the
projected human growth especially in coastal areas, such impacts from
recreation and other uses are expected to continue.
Other Natural and Unnatural Changes to Habitat
Natural changes to vegetation from environmental factors,
succession, or other causes may now be a threat to the Miami blue
because of its severely reduced range, few populations, and limited
dispersal capabilities. Suitable and occupied habitat in KWNWR and
other coastal areas is dynamic and fluctuating, influenced by a variety
of environmental factors (e.g., storm surge, wind, precipitation). In
2010, substantial changes in habitat conditions on Boca Grande occurred
with the proliferation of Galactia striata, a native climbing vine (T.
Wilmers, pers. comm. 2010a; P. Cannon, pers. comm. 2010b, 2010h, 2010i,
2010j). The vine has enveloped a substantial amount of blackbead,
occurring on about 40 percent of the blackbead growing on the seaward
side at the dune interface (T. Wilmers, pers. comm. 2010a). Wilmers
(pers. comm. 2010a) believes that the extensive growth was likely
fueled by the markedly higher precipitation during September and
October 2010 (3.47 and 2.22 inches [8.81 and 5.64 cm], respectively,
above normal in Key West). Under favorable conditions, the vine first
grows in the dune, then sprawls landward laterally, eventually
ascending and blanketing blackbead (T. Wilmers, pers. comm. 2010a).
While climbing vines can proliferate before eventually dying back,
Wilmers (pers. comm. 2010a) states that the intense proliferation in
2010 is unprecedented in his 25 years of work in the area. It is
unclear what steps are needed at this time. Left unchecked, this
proliferation has the potential to impact host plants and affect the
butterfly's ability to persist on some islands.
Invasive and Exotic Vegetation
Displacement of native plants including host plants by invasive
exotic species, a common problem throughout south Florida, also
possibly contributed to habitat loss of the Miami blue. In coastal
areas where undeveloped land remains, the Miami blue's larval food
plants are likely to be displaced by invasive exotic plants, such as
Brazilian pepper, Australian pine (Casuarina equesitifolia), Asian
nakedwood (Colubrina asiatica), cat-claw vine (Macfadyena ungius-cati),
wedelia (Spahneticola trilobata), largeleaf lantana (Lantana camara),
Portia tree (Thespesia populnea), wild indigo (Indigofera spicata),
beach naupaka (Scaevola taccada), and several species of invasive
grasses. Although we do not have direct evidence of exotic species
displacing host plants or nectar sources, we recognize this as a
potential threat, due to the magnitude of this problem in south
Florida.
Pesticides
Efforts to control salt marsh mosquitoes, Aedes taeniorhynchus,
among others, have increased as human activity and population have
increased in south Florida. To control mosquito populations, second-
generation organophosphate (naled) and pyrethroid (permethrin)
adulticides are applied by mosquito control districts throughout south
Florida. The use of pesticides (applied using both aerial and ground-
based methods) to control mosquitoes presents a potential risk to
nontarget species, including the Miami blue butterfly.
The potential for mosquito control chemicals to drift into
nontarget areas and persist for varying periods of time has been well
documented. Hennessey and Habeck (1989, pp. 1-22; 1991, pp. 1-68) and
Hennessey et al. (1992, pp. 715-721) illustrated the presence of
mosquito spray residues long after application in habitat of the Schaus
swallowtail and other imperiled species in both the upper (Crocodile
Lake NWR, North Key Largo) and lower Keys (National Key Deer Refuge
[NKDR], Big Pine Key). Residues of aerially applied naled were found 6
hours after application in a pineland area that was 820 yards (750
meters) from the target area; residues of fenthion (an adulticide no
longer used in the Keys) applied via truck were found up to 55 yards
(50 meters) downwind in a hammock area 15 minutes after application in
adjacent target areas (Hennessey et al. 1992, pp. 715-721).
More recently, Pierce (2009, pp. 1-17) monitored naled and
permethrin
[[Page 49559]]
deposition following application in and around NKDR from 2007 to 2009.
Permethrin, applied by truck, was found to drift considerable distances
from target areas with residues that persisted for weeks. Naled,
applied by plane, was also found to drift into nontarget areas but was
much less persistent exhibiting a half-life of approximately 6 hours.
In 2009, Tim Bargar (U.S. Geological Survey, pers. comm. 2011)
conducted two field trials on NKDR that detected significant naled
residues at locations within nontarget areas on the refuge that were up
to 440 yards (402 m) from the edge of zones targeted for aerial
applications.
In addition to mosquito control chemicals entering nontarget areas,
the toxic effects of mosquito control chemicals to nontarget organisms
have also been documented. Lethal effects on nontarget Lepidoptera have
been attributed to fenthion and naled in both south Florida and the
Keys (Emmel 1991, pp. 12-13; Eliazar and Emmel 1991, pp. 18-19; Eliazar
1992, pp. 29-30). In the lower Keys, Salvato (2001, pp. 8-14) and
Hennessey and Habeck (1991, p. 14) suggested that declines in
populations of the Florida leafwing (now a Federal candidate) were also
partly attributable to mosquito control chemical applications. Salvato
(2001, p. 14; 2002, pp. 56-57) found populations of the Florida
leafwing (on Big Pine Key within NKDR) to increase during drier years
when adulticide applications over the pinelands decreased, although
Bartram's hairstreak did not follow this pattern. It is important to
note that vulnerability to chemical exposure may vary widely between
species, and current application regimes do not appear to affect some
species as strongly as others (Calhoun et al. 2002, p. 18; Breidenbaugh
and De Szalay 2010, pp. 594-595; Rand and Hoang 2010, pp. 14-17, 20;
Hoang et al. 2011, pp. 997-1005).
Dose-dependent decreases in brain cholinesterase activity in great
southern white butterflies (Ascia monuste) exposed to naled have been
measured in the laboratory (T. Bargar, pers. comm. 2011). An inhibition
of cholinesterase, which is the primary mode of action of naled,
prevents an important neurotransmitter, acetylcholine, from being
metabolized, causing uncontrolled nerve impulses that may result in
erratic behavior and, if severe enough, mortality. From these data, it
was determined that significant mortality was associated with
cholinesterase activity depression of at least 27 percent (T. Bargar,
pers. comm. 2011). In a subsequent field study on NKDR, adult great
southern white and Gulf fritillary (Agraulis vanillae) butterflies were
placed in field enclosures at both target and nontarget areas during
aerial naled application. The critical level of cholinesterase
inhibition (27 percent) was exceeded in the majority of butterflies
from the target areas, as well as in a large proportion of butterflies
from the nontarget areas (T. Bargar, pers. comm. 2011). During the same
field experiment, great southern white and Gulf fritillary larvae were
also exposed in the field during aerial naled application and exhibited
mortality at both target and nontarget sites (T. Bargar, pers. comm.
2011).
In a laboratory study, Rand and Hoang (2010, pp. 1-33) and Hoang et
al. (2011, pp. 997-1005) examined the effects of exposure to naled,
permethrin, and dichlorvos (a breakdown product of naled) on both
adults and larvae of five Florida native butterfly species (common
buckeye (Junonia coenia), painted lady (Vanessa cardui), zebra longwing
(Heliconius charitonius), atala hairstreak (Eumaeus atala), and white
peacock (Anartia jatrophae)). The results of this study indicated that,
in general, larvae were slightly more sensitive to each chemical than
adults, but the differences were not significant. Permethrin was
generally the most toxic chemical to both larvae and adults, although
the sensitivity between species varied.
The laboratory toxicity data generated by this study were used to
calculate hazard quotients (concentrations in the environment/
concentrations causing an adverse effect) to assess the risk that
concentrations of naled and permethrin found in the field pose to
butterflies. A hazard quotient that exceeds one indicates that the
environmental concentration is greater than the concentration known to
cause an adverse effect (mortality in this case), thus indicating
significant risk to the organism. Environmental exposures for naled and
permethrin were taken from Zhong et al. (2010, pp. 1961-1972) and
Pierce (2009, pp. 1-17), respectively, and represent the highest
concentrations of each chemical that were quantified during field
studies in the Keys. When using the lowest median lethal concentrations
from the laboratory study, the hazard quotients for permethrin were
greater than one for each adult butterfly, indicating a significant
risk of toxicity to each species. In the case of naled, significant
risk to the zebra longwing was predicted based on its hazard quotient
exceeding one.
From 2006 to 2008, Zhong et al. (2010, pp. 1961-1972) investigated
the impact of single aerial applications of naled on Miami blue larvae
in the field. The study was conducted in North Key Largo in cooperation
with the Florida Keys Mosquito Control District (FKMCD) and used
experimentally placed Miami blue larvae that were reared in captivity.
The study involved 15 test stations: 9 stations in the target zone, 3
stations considered to be susceptible to drift (2 stations directly
adjacent to the spray zone and 1 station 12 miles (19.3 km) southwest
of the spray zone), and 3 field reference stations (25 miles (40.2 km)
southwest of the spray zone). Survival of butterfly larvae in the
target zone was 73.9 percent, which was significantly lower than both
the drift zone (90.6 percent) and the reference zone (100 percent),
indicating that direct exposure to naled poses significant risk to
Miami blue larvae. In addition to observing elevated concentrations of
naled at test stations in the target zone, 9 of 18 samples in the drift
zone also exhibited detectable concentrations, once again exhibiting
the potential for mosquito control chemicals to drift into nontarget
areas.
Based on these studies, it can be concluded that mosquito control
activities that involve the use of both aerial and ground-based
spraying methods have the potential to deliver pesticides in quantities
sufficient to cause adverse effects to nontarget species in both target
and nontarget areas. It should be noted that many of the studies
referenced above dealt with single application scenarios and examined
effects on only one to two butterfly life stages. Under a realistic
scenario, the potential exists for exposure to all life stages to occur
over multiple applications in a season. In the case of a persistent
compound like permethrin where residues remain on vegetation for weeks,
the potential exists for nontarget species to be exposed to multiple
pesticides within a season (e.g., permethrin on vegetation coupled with
aerial exposure to naled).
Aspects of the Miami blue's natural history may increase its
potential to be exposed to and affected by mosquito control pesticides
and other chemicals. For example, host plants and nectar sources are
commonly found at disturbed sites and often occur along roads in
developed areas, where chemicals are applied. Ants associated with the
Miami blue (see Interspecific relationships) may be affected in unknown
ways. Host plant and nectar source availability may also be indirectly
affected through impacts on pollinators. Carroll and Loye (2006, pp.
19, 24) and others (Emmel 1991, p. 13; Glassberg and Salvato 2000, p.
7; Calhoun et al. 2002, p. 18) suggested
[[Page 49560]]
that the Miami blue butterfly may be more susceptible to pesticides
than perhaps other lycaenids (e.g., the silver-banded hairstreak)
because Miami blue larvae leave entrance holes open in seed pods to
allow access for attending ants. Ants and larvae of the Miami blue on
balloonvine were found to die when roadside spraying for mosquito
control began in late spring, but larvae of the silver-banded
hairstreak (also on balloonvine) apparently survived subsequent
spraying (Emmel 1991, p. 13). However, Minno (pers. comm. 2010) argues
that larvae using balloonvine pods would be protected from the effects
of pesticides because the pods have internal partitions and exposure
would be limited due to the size of the entrance hole.
No mosquito control pesticides are used within KWNWR. At BHSP, the
only application of adulticides (permethrin) is occasional truck-based
spraying in the ranger residence areas (E. Kiefer, pers. comm. 2011a).
Mosquito control practices currently pose no risk to the Miami blue
within KWNWR or in formerly occupied habitat at BHSP. However, mosquito
control activities, including the use of larvicides and adulticides,
are being implemented within suitable and potential habitat for the
Miami blue elsewhere in its range (Carroll and Loye 2006, pp. 14-15).
The findings of Zhong et al. (2010, pp. 1961-1972) and Pierce (2009,
pp. 1-17) along with other studies suggest that aerial or truck-based
applications of mosquito control chemicals may pose a threat to the
Miami blue, if the butterfly exists in other, unknown locations.
Additionally, mosquito control practices potentially may limit
expansion of undocumented populations or colonization of new areas. If
the Miami blue colonizes new areas or if additional populations are
discovered or reintroduced, adjustments in mosquito control (and other)
practices may be needed to help safeguard the subspecies.
Efforts are already underway by multiple agencies and partners to
seek ways to avoid and minimize impacts to the Miami blue and other
imperiled nontarget species. For example, in an effort to reduce the
need for aerial adulticide spraying, the FKMCD is increasing
larviciding activities, which are believed to have less of an
ecological impact on wilderness islands near NKDR and GWHNWR (FKMCD
2009, pp. 3-4). This effort has led to a reduction in area receiving
adulticide treatment on Big Pine Key, No Name Key, and Torch Key (FKMCD
2009, p. 17). Another example is the Florida Coordinating Council on
Mosquito Control (FCCMC), including the Imperiled Species Subcommittee,
which was initially formed to resolve the conflict between mosquito
control spraying and the reintroduction of Miami blues to their
historical range (FWC 2010, p. 9).
The FWC's management plan for the Miami blue also recommends the
use of no-spray zones for all pesticides and use of buffers at or
around Miami blue populations and other conservation measures (FWC
2010, pp. ii-41). However, there are no specific binding or mandatory
restrictions to prohibit such practices or encourage other beneficial
measures. The FWC plan suggests that an aerial no-spray buffer zone of
820 yards (750 m) be established around Miami blue populations where
possible and that buffer zones for truck-based applications of
adulticides also be established (FWC 2010, p. 17). The FCCMC also
recommends that the appropriate width of buffer zones be determined by
future research. The Service is supporting research to characterize
drift from truck-based spraying methods. The data from this study will
aid in better determining appropriate buffer distances around sensitive
areas.
In summary, although substantial progress has been made in reducing
impacts, the potential effects of mosquito control applications and
drift residues remain a threat to the Miami blue. We will continue to
work with the mosquito control districts and other partners and
stakeholders to reduce threats wherever possible.
Effects of Small Population Size and Isolation
The Miami blue is vulnerable to extinction due to its severely
reduced range, small population size, metapopulation structure, few
remaining populations, and relative isolation. In general, isolation,
whether caused by geographic distance, ecological factors, or
reproductive strategy, will likely prevent the influx of new genetic
material and can result in low diversity, which may impact viability
and fecundity (Chesser 1983, pp. 66-77). Extinction risk can increase
significantly with decreasing heterozygosity as was reported for the
Glanville fritillary (Saccheri et al. 1998, pp. 491-494). Distance
between metapopulations and colonies within those metapopulations and
the small size of highly sporadic populations can make recolonization
unlikely if populations are extirpated. Fragmentation of habitat and
aspects of the butterfly's natural history (e.g., limited dispersal,
reliance on host plants) can contribute to and exacerbate threats.
Estimated abundance of the Miami blue is not known, but may number
in the hundreds, and at times, possibly higher. Although highly
dependent upon species, a population of 1,000 has been suggested as
marginally viable for an insect (D. Schweitzer, The Nature Conservancy,
pers. comm. 2003). Schweitzer (pers. comm. 2003) has also suggested
that butterfly populations of less than 200 adults per generation would
have difficulty surviving over the long term. In comparison, in a
review of 27 recovery plans for listed insect species, Schultz and
Hammond (2003, p. 1377) found that 25 plans broadly specified
metapopulation features in terms of requiring that recovery include
multiple population areas (the average number of sites required was
8.2). The three plans that quantified minimum population sizes as part
of their recovery criteria for butterflies ranged from 200 adults per
site (Oregon silverspot [Speyeria zerene hippolyta]) to 100,000 adults
(Bay checkerspot [Euphydryas editha bayensis]) (Schulz and Hammond
2003, pp. 1374-1375).
Schultz and Hammond (2003, pp. 1372-1385) used population viability
analyses to develop quantitative recovery criteria for insects whose
population sizes can be estimated and applied this framework in the
context of the Fender's blue (Icaricia icarioides fenderi), a butterfly
listed as endangered in 2000 due to its small population size and
limited remaining habitat. They found the Fender's blue to be at high
risk of extinction at most of its sites throughout its range despite
that fact that the average population at 12 sites examined ranged from
5 to 738 (Schulz and Hammond 2003, pp. 1377, 1379). Of the three sites
with populations greater than a few hundred butterflies, only one of
these had a reasonably high probability of surviving the next 100 years
(Schulz and Hammond 2003, p. 1379). Although the conservation needs and
biology of the Miami blue and Fender's blue are undoubtedly different,
the two lycaenids share characteristics: both have limited dispersal,
and most remaining habitat patches are completely isolated.
Losses in diversity within historical and current populations of
the Miami blue butterfly have already occurred. Historical populations
were genetically more diverse than two contemporary populations (BHSP
and KWNWR) (Saarinen 2009, p. 48). Yet together, between the two
contemporary populations, the Miami blue had retained a significant
amount of genetic diversity from its historical values
[[Page 49561]]
(Saarinen 2009, p. 51). Despite likely fluctuations in population size,
the BHSP population had retained an adequate amount of genetic
diversity to maintain the population (Saarinen 2009, p. 77). Overall,
patterns of genetic diversity in the BHSP population (mean overall
observed heterozygosity of 39.5 percent) were similar to or slightly
lower than other nonmigratory butterfly species' studies utilizing
microsatellite markers (Saarinen 2009, pp. 50, 74-75). Unfortunately,
the BHSP population may now be lost. The extant KWNWR population is
more genetically diverse (mean observed heterozygosity of 51 percent
vs. 39.5 percent for BHSP) (Saarinen 2009, p. 75).
The Miami blue appears to have been impacted by relative isolation.
No gene flow has occurred between contemporary populations (Saarinen et
al. 2009a, p. 36). Saarinen (2009, p. 79) suggests that the separation
was recent. While historical populations may have once linked the two
contemporary populations, the recent absence of populations between
KWNWR and BHSP appears to have broken the gene flow (Saarinen 2009, p.
79). Based upon modeling with a different butterfly species, Fleishman
et al. (2002, pp. 706-716) argued that factors such as habitat quality
may influence metapopulation dynamics, driving extinction and
colonization processes, especially in systems that experience
substantial natural and anthropogenic environmental variability (see
Environmental stochasticity below).
According to Saarinen et al. (2009a, p. 36), the severely reduced
size of the existing populations suggests that genetic factors along
with environmental stochasticity may already be affecting the
persistence of the Miami blue. However, they also suggested that, in
terms of extinction risk, a greater short-term problem for the two
contemporary natural populations (BHSP and KWNWR) may be the lack of
gene flow rather than the current effective population size (Saarinen
et al. 2009a, p. 36). If only one or two metapopulations remain, it is
absolutely critical that remaining genetic diversity and gene flow are
retained. Conservation decisions to augment or reintroduce populations
should not be made without careful consideration of habitat
availability, genetic adaptability, the potential for the introduction
of maladapted genotypes, and other factors (Frankham 2008, pp. 325-333;
Saarinen et al. 2009a, p. 36).
Aspects of Its Natural History
Aspects of the Miami blue's natural history may increase the
likelihood of extinction. Cushman and Murphy (1993, p. 40) argued that
dispersal is essential for the persistence of isolated populations.
Input of individuals from neighboring areas can bolster dwindling
numbers and provide an influx of genetic diversity, increasing fitness
and population viability. The tendency for lycaenids to be
comparatively sedentary should result in less frequent recolonization,
less influx of individuals, and reduced gene flow between populations
(Cushman and Murphy 1993, p. 40). In short, taxa with limited dispersal
abilities may be far more susceptible to local extinction events than
taxa with well-developed abilities (Cushman and Murphy 1993, p. 40).
Lycaenids with a strong dependence on ants may be more sensitive to
environmental changes and thus more prone to endangerment and
extinction than species not tended by ants (and non-lycaenids in
general) (Cushman and Murphy 1993, pp. 37, 41). Their hypothesis is
based on the probability that the combination of both the right food
plant and the presence of a particular ant species may occur relatively
infrequently in the landscape. Selection may favor reduced dispersal by
ant-associated lycaenids due to the difficulty associated with locating
patches that contain the appropriate combination of food plants and
ants (Cushman and Murphy 1993, pp. 39-40). Although significant
research on the relationship between Miami blue larvae and ants has
been conducted, this association is still not completely understood.
Lycaenid traits (sedentary, host-specific, symbiotic with ants) that
result in isolated populations of variable sizes may serve to limit
genetic exchange (Cushman and Murphy 1993, pp. 37, 39-40). The Miami
blue possesses several of these traits, all of which may increase
susceptibility and contribute to imperilment.
Environmental Stochasticity
The climate of the Keys is driven by a combination of local,
regional, and global events, regimes, and oscillations. There are three
main ``seasons'': (1) The wet season, which is hot, rainy, and humid
from June through October, (2) the official hurricane season that
extends one month beyond the wet season (June 1 through November 30)
with peak season being August and September, and (3) the dry season,
which is drier and cooler from November through May. In the dry season,
periodic surges of cool and dry continental air masses influence the
weather with short-duration rain events followed by long periods of dry
weather.
Environmental factors have likely impacted the Miami blue and its
habitat within its historical range. A hard freeze in the late 1980s
likely contributed to the Miami blue's decline (L. Koehn, pers. comm.
2002) presumably due to loss of larval host plants in south Florida.
Prolonged cold temperatures in January 2010 and December 2010 through
January 2011 may have also impacted the remaining metapopulations in
the Keys. Unseasonably cold temperatures during winter 2010 (in
combination with impacts from iguanas) resulted in a substantial loss
of nickerbean and nectar sources at BHSP. This reduction, albeit
temporary, may have severely impacted an already depressed Miami blue
population on the island. Similarly, extended dry conditions and
drought can affect the availability of host plants and nectar sources
and affect butterfly populations (Emmel and Daniels 2004, pp. 13-14,
17). Depressed numbers of the Miami blue at BHSP in 2008 were
attributed to severe drought (Emmel and Daniels 2009, p. 4).
The Keys are regularly threatened by tropical storms and
hurricanes. No area of the Keys is more than 20 feet (6.1 m) above sea
level (and many areas are only a few feet (meters) in elevation). These
tropical systems have affected the Miami blue and its habitat. Calhoun
et al. (2002, p. 18) indicated that Hurricane Andrew in 1992 may have
negatively impacted the majority of Miami blue populations in southern
Florida. In 2005, four hurricanes (Katrina, Dennis, Rita, and Wilma)
affected habitat at BHSP, resulting in reduced abundance of Miami blues
following the storms that continued throughout 2006 (Salvato and
Salvato 2007, p. 160) and beyond (Emmel and Daniels 2009, p. 4). A
significant portion of the nickerbean and large stands of nectar plants
at BHSP were temporarily damaged by the storms, including roughly 50
percent of the vegetation on the southern side of the island (Salvato
and Salvato 2007, p. 157). Although the host plant quickly recovered
following the storms (Salvato and Salvato 2007, p. 160), the Miami blue
never fully recolonized several parts of the island (Emmel and Daniels
2009, p. 4).
Similarly, Hurricane Wilma heavily damaged blackbead across many
islands within KWNWR (Cannon et al. 2010, p. 850). Although the
hurricane severely damaged or killed much of the Miami blue host plant
on KWNWR, it is also believed to have enhanced or created many new
habitats across the islands by clearing older vegetation and opening
patches for growth of host plant and nectar sources (Cannon et al.
2010, p.
[[Page 49562]]
852). Cannon et al. (2010, p. 852) suggest that the proximity and
circular arrangement of these islands may provide some safeguard during
mild or moderate storms. Given enough resiliency in extant populations,
certain storm regimes may benefit populations over some timeframe if
these events result in disturbances that favor host plants and other
habitat components.
According to the Florida Climate Center, Florida is by far the most
vulnerable State in the United States to hurricanes and tropical storms
(http://coaps.fsu.edu/climate_center/tropicalweather.shtml). Based on
data gathered 1856-2008, Klotzbach and Gray (2009, p. 28) calculated
the climatological and current-year probabilities for each State being
impacted by a hurricane and major hurricane. Of the coastal States
analyzed, Florida had the highest climatological probabilities, with a
51 percent probability of a hurricane and a 21 percent probability of a
major hurricane over a 52-year time span. Florida had a 45 percent
current-year probability of a hurricane and an 18 percent current-year
probability of a major hurricane (Klotzbach and Gray 2009, p. 28).
Given the Miami blue's low population size and few isolated
occurrences, the subspecies is at substantial risk from hurricanes,
storm surges, or other extreme weather. Depending on the location and
intensity of a hurricane or other severe weather event, it is possible
that the Miami blue could be extirpated or could become extinct.
Because it has poor dispersal capabilities, natural recolonization of
potentially suitable sites is anticipated to be unlikely or exceedingly
slow at best.
Other processes to be affected by climate change include
temperatures, rainfall (amount, seasonal timing, and distribution), and
storms (frequency and intensity). Temperatures are predicted to rise
from 2 [deg]C to 5 [deg]C for North America by the end of this century
(IPCC 2007, pp. 7-9, 13). Based upon modeling, Atlantic hurricane and
tropical storm frequencies are expected to decrease (Knutson et al.
2008, pp. 1-21). By 2100, there should be a 10-30 percent decrease in
hurricane frequency with a 5-10 percent wind increase. This is due to
more hurricane energy available for intense hurricanes. However,
hurricane frequency is expected to drop due to more wind shear impeding
initial hurricane development. In addition to climate change, weather
variables are extremely influenced by other natural cycles, such as El
Ni[ntilde]o Southern Oscillation with a frequency of every 4-7 years,
solar cycle (every 11 years), and the Atlantic Multi-decadal
Oscillation. All of these cycles influence changes in Floridian
weather. The exact magnitude, direction, and distribution of all of
these changes at the regional level are difficult to predict.
We have identified a wide array of natural or manmade factors
affecting the continued existence of the Miami blue butterfly. These
threats have operated in the past, are impacting the subspecies now,
and will continue to impact the species in the foreseeable future.
Based on our analysis of the best available information, we have no
reason to believe that natural or manmade factors will change in the
foreseeable future.
Determination of Status
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the Miami blue butterfly. The habitat and range of the subspecies
are threatened with destruction, modification, and curtailment from
human population growth, associated development and agriculture, and
environmental effects resulting from climatic change. Due to the few
metapopulations, small population size, restricted range, and
remoteness of occupied habitat, collection is a significant threat to
the subspecies and could potentially occur at any time. Additionally,
the subspecies is currently threatened by a wide array of natural and
manmade factors. Existing regulatory mechanisms do not provide adequate
protection for the subspecies. As a result, impacts from increasing
threats, singly or in combination, are likely to result in the
extinction of the subspecies because the magnitude of threats is high.
Section 3 of the Endangered Species Act defines an endangered
species as ``* * * any species which is in danger of extinction
throughout all or a significant portion of its range'' and a threatened
species as ``* * * any species which is likely to become an endangered
species within the foreseeable future throughout all or a significant
portion of its range.'' Based on the immediate and ongoing significant
threats to the Miami blue butterfly throughout its entire occupied
range and the fact that the subspecies is restricted to only one or
possibly two populations, we have determined that the subspecies is in
danger of extinction throughout all of its range. Since threats extend
throughout the entire range, it is unnecessary to determine if the
Miami blue butterfly is in danger of extinction throughout a
significant portion of its range. Therefore, on the basis of the best
available scientific and commercial information, we have determined
that the Miami blue butterfly meets the definition of an endangered
species under the Act. Consequently, we are listing the Miami blue
butterfly as an endangered species throughout its entire range.
Reasons for Emergency Determination
Under section 4(b)(7) of the Act and regulations at 50 CFR 424.20,
we may emergency list a species if the threats to the species
constitute an emergency posing a significant risk to its well-being.
Such an emergency listing expires 240 days following publication in the
Federal Register unless, during this 240-day period, we list the
species following the normal listing procedures. Below, we discuss the
reasons why emergency listing the Miami blue butterfly as endangered is
warranted. In accordance with the Act, if at any time after we publish
this emergency rule, we determine that substantial evidence does not
exist to warrant such a rule, we will withdraw it.
In making this determination, we have carefully assessed the best
scientific and commercial information available regarding the past,
present, and future threats faced by the Miami blue butterfly. The only
confirmed metapopulation of Miami blue is currently restricted to a
few, small insular areas in the extreme southern portion of its
historical range. The range of this butterfly, which once extended from
the Keys north along the Florida coasts to about St. Petersburg and
Daytona, is now substantially reduced, with an estimated > 99 percent
decline in area occupied. Population size is unknown, but estimated to
be in the hundreds. Since only one or possibly two small
metapopulations remain in KWNWR, the Miami blue butterfly is imminently
threatened by its restricted range and the combined influences of
habitat destruction or modification, impacts by iguanas, accidental
harm from humans, loss of genetic heterogeneity, and catastrophic
environmental events. Illegal collection could cause severe impacts,
given the few populations and individuals remaining. Therefore, we find
these threats constitute an immediate and significant risk to the well-
being of the species and that extinction of the Miami blue butterfly
may occur at any time.
We believe that the survival of the Miami blue now depends on
protecting the species' occupied and suitable habitat from further
degradation and fragmentation; restoring potentially suitable habitat
within its historical range; removing and reducing threats from
iguanas, pesticides, and accidental
[[Page 49563]]
harm from humans; increasing the current population in size; reducing
the threats of illegal collection; retaining the remaining genetic
diversity; and, establishing populations at additional locations. The
survey and monitoring efforts and scientific studies conducted to date,
when combined with other available historical information, make it
clear that the Miami blue butterfly is on the brink of extinction.
By emergency listing the Miami blue butterfly as an endangered
subspecies, we believe the protections (through sections 7, 9, and 10
of the Act) and recognition that immediately become available to the
subspecies will increase the likelihood that it can be saved from
extinction and ultimately be recovered. In addition, if protections
remain in place after the 240-day period, recovery funds may become
available, which could facilitate recovery actions (e.g., funding for
additional surveys, management needs, research, captive propagation and
reintroduction, monitoring) (see Available Conservation Measures).
The Service acknowledges that it cannot fully address some of the
natural threats facing the subspecies (e.g., hurricanes, tropical
storms) or even some of the other significant, long-term threats (e.g.,
climatic changes, sea-level rise). However, through emergency listing,
we provide immediate protection to the known population(s) and any new
population of the subspecies that may be discovered (see section 9 of
Available Conservation Measures below). With emergency listing, we can
also influence Federal actions that may potentially impact the
subspecies (see section 7 below); this is especially valuable if it is
found at additional locations. With emergency listing, we are also
better able to deter illicit collection and trade.
Through this action, the Miami blue and the three butterflies that
are similar in appearance will receive immediate protection from
collection, possession, and trade (through sections 9 and 10 of the
Act). At present, the three similar butterflies are not protected by
the State. Extending the prohibitions of collection, possession, and
trade to the three similar butterflies provides greater protection to
the Miami blue. This immediate protection will help to deter those who
might otherwise seek to collect the Miami blue before a proposed rule
could be finalized (i.e., through the normal listing process). At this
time, the normal listing timeframe and process is insufficient to
prevent losses that may result in extinction. We believe emergency
listing will partially alleviate some of the imminent threats that now
pose a significant risk to the survival of the subspecies.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness and
conservation by Federal, State, Tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and requires that recovery actions be carried out for all listed
species. The protection required by Federal agencies and the
prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
species' decline by addressing the threats to its survival and
recovery. The goal of this process is to restore listed species to a
point where they are secure, self-sustaining, and functioning
components of their ecosystems.
Recovery planning includes the development of a recovery outline
shortly after a species is listed, preparation of a draft and final
recovery plan, and revisions to the plan as significant new information
becomes available. The recovery outline guides the immediate
implementation of urgent recovery actions and describes the process to
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species,
measurable criteria that determine when a species may be downlisted or
delisted, and methods for monitoring recovery progress. Recovery plans
also establish a framework for agencies to coordinate their recovery
efforts and provide estimates of the cost of implementing recovery
tasks. Recovery teams (composed of species experts, Federal and State
agencies, nongovernment organizations, and stakeholders) are often
established to develop recovery plans. When completed, the recovery
outline, draft recovery plan, and the final recovery plan will be
available on our Web site (http://www.fws.gov/endangered), or from our
South Florida Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
Through this listing, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. Additionally,
under section 6 of the Act, we would be able to grant funds to the
State of Florida for management actions promoting the conservation of
the Miami blue. Information on our grant programs that are available to
aid species recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in
recovery efforts for the Miami blue. Additionally, we invite you to
submit any new information on the subspecies, its habitat, or threats
whenever it becomes available and any information you may have for
recovery planning purposes; if you submit information after the date
listed in the DATES section above, you will need to send it to the
street address provided in the FOR FURTHER INFORMATION CONTACT section.
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as
endangered or threatened and with respect to its critical habitat, if
any is being designated. Regulations implementing this interagency
cooperation provision of the Act are codified at 50 CFR part 402.
Section 7(a)(4) requires Federal agencies to confer informally with us
on any action that is likely to jeopardize the continued existence of a
species proposed for listing or result in destruction or adverse
modification of proposed critical habitat. If a species is listed
subsequently, section 7(a)(2) of the Act requires Federal agencies to
[[Page 49564]]
ensure that activities they authorize, fund, or carry out are not
likely to jeopardize the continued existence of such a species or to
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with us.
Federal agency actions that may require conference or consultation
as described in the preceding paragraph include the issuance of Federal
funding, permits, or authorizations for construction, clearing,
development, road maintenance, pesticide registration, pesticide use
(on Federal land or with Federal funding), agricultural assistance
programs, Federal loan and insurance programs, Federal habitat
restoration programs, and scientific and special uses. Activities will
trigger consultation under section 7 of the Act if they may affect the
Miami blue butterfly, as addressed in this emergency rule.
Jeopardy Standard
Prior to and following listing, the Service applies an analytical
framework for jeopardy analyses that relies heavily on the importance
of core area populations to the survival and recovery of the species.
The section 7(a)(2) analysis is focused not only on these populations
but also on the habitat conditions necessary to support them.
The jeopardy analysis usually expresses the survival and recovery
needs of the species in a qualitative fashion without making
distinctions between what is necessary for survival and what is
necessary for recovery. Generally, if a proposed Federal action is
incompatible with the viability of the affected core area
population(s), inclusive of associated habitat conditions, a jeopardy
finding is considered to be warranted, because of the relationship of
each core area population to the survival and recovery of the species
as a whole.
Section 9 Take
The Act and implementing regulations set forth a series of general
prohibitions and exceptions that apply to all endangered and threatened
wildlife. These prohibitions are applicable to the Miami blue butterfly
immediately through emergency listing. The prohibitions of section
9(a)(2) of the Act, codified at 50 CFR 17.21 for endangered wildlife,
in part, make it illegal for any person subject to the jurisdiction of
the United States to take (includes harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect, or to attempt any of these),
import or export, deliver, receive, carry, transport, or ship in
interstate or foreign commerce in the course of commercial activity, or
sell or offer for sale in interstate or foreign commerce any listed
species. It also is illegal to possess, sell, deliver, carry,
transport, or ship any such wildlife that has been taken illegally.
Further, it is illegal for any person to attempt to commit, to solicit
another person to commit, or to cause to be committed, any of these
acts. Certain exceptions apply to our agents and State conservation
agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. We codified
the regulations governing permits for endangered species at 50 CFR
17.22. Such permits are available for scientific purposes, to enhance
the propagation or survival of the species, or for incidental take in
the course of otherwise lawful activities.
It is our policy, published in the Federal Register on July 1, 1994
(59 FR 34272), to identify, to the maximum extent practicable at the
time a species is listed, those activities that would or would not
constitute a violation of section 9 of the Act and associated
regulations at 50 CFR 17.21. The intent of this policy is to increase
public awareness of the effect of this emergency listing on proposed
and ongoing activities within a species' range. We believe, based on
the best available information, that the following actions will not
result in a violation of the provisions of section 9 of the Act,
provided these actions are carried out in accordance with existing
regulations and permit requirements, if applicable:
(1) Possession, delivery, or movement, including interstate
transport and import into or export from the United States, involving
no commercial activity, of dead specimens of this taxon that were
collected or legally acquired prior to the effective date of this rule.
(2) Actions that may affect the Miami blue that are authorized,
funded, or carried out by Federal agencies when such activities are
conducted in accordance with an incidental take statement issued by us
under section 7 of the Act.
(3) Actions that may affect the Miami blue that are not authorized,
funded, or carried out by a Federal agency, when the action is
conducted in accordance with an incidental take permit issued by us
under section 10(a)(1)(B) of the Act. Applicants design a Habitat
Conservation Plan (HCP) and apply for an incidental take permit. These
HCPs are developed for species listed under section 4 of the Act and
are designed to minimize and mitigate impacts to the species to the
greatest extent practicable.
(4) Actions that may affect the Miami blue that are conducted in
accordance with the conditions of a section 10(a)(1)(A) permit for
scientific research or to enhance the propagation or survival of the
subspecies.
(5) Captive propagation activities involving the Miami blue that
are conducted in accordance with the conditions of a section
10(a)(1)(A) permit, our ``Policy Regarding Controlled Propagation of
Species Listed Under the Endangered Species Act,'' and in cooperation
with the State of Florida.
(6) Low-impact, infrequent, dispersed human activities on foot
(e.g., bird watching, butterfly watching, sightseeing, backpacking,
photography, camping, hiking) in areas occupied by the Miami blue or
where its host and nectar plants are present.
(7) Activities on private lands that do not result in take of the
Miami blue butterfly, such as normal landscape activities around a
personal residence, construction that avoids butterfly habitat, and
pesticide/herbicide application consistent with label restrictions, if
applied in areas where the subspecies is absent.
We believe the following activities would be likely to result in a
violation of section 9 of the Act; however, possible violations are not
limited to these actions alone:
(1) Unauthorized possession, collecting, trapping, capturing,
killing, harassing, sale, delivery, or movement, including interstate
and foreign commerce, or harming or attempting any of these actions, of
Miami blue butterflies at any life stage without a permit (research
activities where Miami blue butterflies are surveyed, captured
(netted), or collected will require a permit under section 10(a)(1)(A)
of the Act).
(2) Incidental take of Miami blue butterfly without a permit
pursuant to section 10 (a)(1)(B) of the Act.
(3) Sale or purchase of specimens of this taxon, except for
properly documented antique specimens of this taxon at least 100 years
old, as defined by section 10(h)(1) of the Act.
(4) Unauthorized destruction or alteration of Miami blue butterfly
habitat (including unauthorized grading, leveling, plowing, mowing,
burning, trampling, herbicide spraying, or other destruction or
modification of occupied or potentially occupied habitat or pesticide
application in known occupied habitat) in ways that kills or injures
eggs, larvae, or adult Miami blue
[[Page 49565]]
butterflies by significantly impairing the subspecies' essential
breeding, foraging, sheltering, or other essential life functions.
(5) Use of pesticides/herbicides that are in violation of label
restrictions resulting in take of Miami blue butterfly or ants
associated with the subspecies in areas occupied by the butterfly.
(6) Unauthorized release of biological control agents that attack
any life stage of this taxon or ants associated with the Miami blue.
(7) Removal or destruction of native food plants being utilized by
Miami blue butterfly, including Caesalpinia spp., Cardiospermum spp.,
and Pithecellobium spp., within areas used by this taxon that results
in harm to this butterfly.
(8) Release of exotic species into occupied Miami blue butterfly
habitat that may displace the Miami blue or its native host plants.
We will review other activities not identified above on a case-by-
case basis to determine whether they may be likely to result in a
violation of section 9 of the Act. We do not consider these lists to be
exhaustive, and provide them as information to the public.
You should direct questions regarding whether specific activities
may constitute a future violation of section 9 of the Act to the Field
Supervisor of the Service's South Florida Ecological Services Field
Office (see FOR FURTHER INFORMATION CONTACT). Requests for copies of
regulations regarding listed species and inquiries about prohibitions
and permits should be addressed to the U.S. Fish and Wildlife Service,
Ecological Services Division, Endangered Species Permits, 1875 Century
Boulevard, Atlanta, GA 30345 (Phone 404-679-7313; Fax 404-679-7081).
Critical Habitat and Prudency Determination
Critical habitat and prudency is addressed in the proposed listing
rule, which is published concurrently with this emergency rule. In that
rule, we determine that designation of critical habitat for the Miami
blue butterfly is not prudent due to the increased likelihood and
severity of threats to the subspecies from collection and destruction
of sensitive habitat. Spatially depicting exactly where the subspecies
may or could be found and more widely publicizing maps of specific
areas containing essential features or essential areas is expected to
expose the fragile population and its habitat to greater risks. In
addition, designation of critical habitat will likely exacerbate
enforcement problems.
Similarity of Appearance
Section 4(e) of the Act authorizes the treatment of a species,
subspecies, or population segment as endangered or threatened if: ``(a)
Such species so closely resembles in appearance, at the point in
question, a species which has been listed pursuant to such section that
enforcement personnel would have substantial difficulty in attempting
to differentiate between the listed and unlisted species; (b) the
effect of this substantial difficulty is an additional threat to an
endangered or threatened species; and (c) such treatment of an unlisted
species will substantially facilitate the enforcement and further the
policy of this Act.'' Listing a species as endangered or threatened
under the similarity of appearance provisions of the Act extends the
take prohibitions of section 9 of the Act to cover the species. A
designation of endangered or threatened due to similarity of appearance
under section 4(e) of the Act, however, does not extend other
protections of the Act, such as consultation requirements for Federal
agencies under section 7 and the recovery planning provisions under
section 4(f), that apply to species that are listed as endangered or
threatened under section 4(a). All applicable prohibitions and
exceptions for species listed under section 4(e) of the Act due to
similarity of appearance to a threatened or endangered species will be
set forth in a special rule under section 4(d) of the Act.
There are only slight morphological differences between the Miami
blue and the cassius blue, ceraunus blue, and nickerbean blue, making
it difficult to differentiate between the species, especially due to
their small size. This poses a problem for Federal and State law
enforcement agents trying to stem illegal collection and trade in the
Miami blue. It is quite possible that collectors authorized to collect
similar species may inadvertently (or purposefully) collect the Miami
blue butterfly thinking it was the cassius blue, ceraunus blue, or
nickerbean blue, which also occur in the same geographical area and
habitat type. The listing of these similar blue butterflies as
threatened due to similarity of appearance eliminates the ability of
amateur butterfly enthusiasts and private and commercial collectors to
purposefully or accidentally misrepresent the Miami blue as one of
these other species. The listing will also facilitate Federal and State
law enforcement agents' efforts to curtail illegal possession,
collection, and trade in the Miami blue. At this time, the three
similar butterflies are not protected by the State. Extending the
prohibitions of collection, possession, and trade to the three similar
butterflies through this listing of these species due to similarity of
appearance under section 4(e) of the Act and providing applicable
prohibitions and exceptions under section 4(d) of the Act will provide
greater protection to the Miami blue. For these reasons, we are listing
the cassius blue butterfly (Leptotes cassius theonus), ceraunus blue
butterfly (Hemiargus ceraunus antibubastus), and nickerbean blue
butterfly (Cyclargus ammon) as threatened due to similarity of
appearance to the Miami blue, pursuant to section 4(e) of the Act.
Special Rule Under Section 4(d) of the Act
Whenever a species is listed as a threatened species under the Act,
the Secretary may specify regulations that he deems necessary and
advisable to provide for the conservation of that species under the
authorization of section 4(d) of the Act. These rules, commonly
referred to as ``special rules,'' are found in part 17 of title 50 of
the Code of Federal Regulations (CFR) in sections 17.40-17.48. This
special rule for 17.47, which is reserved, prohibits take of any
cassius blue butterfly (Leptotes cassius theonus), ceraunus blue
butterfly (Hemiargus ceraunus antibubastus), or nickerbean blue
butterfly (Cyclargus ammon) or their immature stages throughout their
ranges in order to protect the Miami blue butterfly from collection,
possession, and trade. In this context, collection and trade are
defined as any activity where cassius blue, ceraunus blue, or
nickerbean blue butterflies or their immature stages are attempted to
be, or are intended to be, kept, traded, sold, or exchanged for goods
or services. Capture of cassius blue, ceraunus blue, or nickerbean blue
butterflies, or their immature stages, is not prohibited if it is
accidental or incidental to otherwise legal collection activities, such
as research, provided the animal is released immediately upon discovery
at the point of capture. Scientific activities involving collection or
propagation of these similarity of appearance butterflies are not
prohibited provided there is prior written authorization from the
Service. All otherwise legal activities involving cassius blue,
ceraunus blue, or nickerbean blue butterflies that are conducted in
accordance with applicable State, Federal, Tribal, and local laws and
regulations are not considered to be take under this regulation.
[[Page 49566]]
Effects of These Rules
Listing the cassius blue, ceraunus blue, and nickerbean blue
butterflies as threatened under the ``similarity of appearance''
provisions of the Act, and the promulgation of a special rule under
section 4(d) of the Act, extend take prohibitions to these species and
their immature stages. Capture of these species, including their
immature stages, is not prohibited if it is accidental or incidental to
otherwise legal collection activities, such as research, provided the
animal is released immediately upon discovery, at the point of capture.
However, this emergency rule establishes immediate prohibitions on the
possession, collection, and trade of these species throughout their
ranges in the United States. Likewise, this emergency rule immediately
prohibits the import and export of these subspecies, and therefore may
have an effect on commercial and non-commercial trade within the United
States.
There are over 60 species and subspecies of butterflies within the
Cyclargus, Leptotes, Hemiargus and Pseudochrysops genera, occurring
domestically and internationally, that could be confused with the Miami
blue butterfly, or the three similarity of appearance butterflies. We
are aware that legal trade in some of these other blue butterflies
exists. To avoid confusion and delays in legal trade, we strongly
recommend maintaining the appropriate documentation and declarations
with legal specimens at all times, especially when importing them into
the United States. Legal trade of other species that may be confused
with the Miami blue butterfly or the three similarity of appearance
butterflies should also comply with the import/export transfer
regulations under 50 CFR 14, where applicable.
All otherwise legal activities that may involve incidental take
(take that results from, but is not the purpose of, carrying out an
otherwise lawful activity) of these similar butterflies, and which are
conducted in accordance with applicable State, Federal, Tribal, and
local laws and regulations, will not be considered take under this
regulation. For example, this special 4(d) rule exempts legal
application of pesticides, yard care, vehicle use, vegetation
management, exotic plant removal, burning, and any other legally
undertaken actions that result in the accidental take of cassius blue,
ceraunus blue, or nickerbean blue butterflies. These actions will not
be considered as violations of section 9 of the Act. We believe that
listing the cassius blue, ceraunus blue, and nickerbean blue
butterflies under the similarity of appearance provision of the Act,
coupled with this special 4(d) rule, will help minimize enforcement
problems and enhance conservation of the Miami blue.
We believe that this provision to allow incidental take of these
three similar butterflies will not pose a threat to the Miami blue
because: (1) Activities such as yard care and vegetation control in
developed or commercial areas that are likely to result in take of the
cassius blue, ceraunus blue, and nickerbean blue are not likely to
affect the Miami blue, and (2) the primary threat that activities
concerning the cassius blue, ceraunus blue, and nickerbean blue
butterflies pose to the Miami blue comes from collection and commercial
trade.
Required Determinations
Clarity of Rule
We are required by Executive Orders 12866 and 12988 and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must: (a) Be logically
organized; (b) Use the active voice to address readers directly; (c)
Use clear language rather than jargon; (d) Be divided into short
sections and sentences; and (e) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in the ADDRESSES section. To
better help us revise the rule, your comments should be as specific as
possible. For example, you should tell us page numbers and the names of
the sections or paragraphs that are unclearly written, which sections
or sentences are too long, the sections where you feel lists or tables
would be useful, etc.
Paperwork Reduction Act (44 U.S.C. 3501, et seq.)
This rule does not contain any new collections of information that
require approval by the Office of Management and Budget (OMB) under the
Paperwork Reduction Act. This rule will not impose new recordkeeping or
reporting requirements on State or local governments, individuals,
businesses, or organizations. We may not conduct or sponsor, and you
are not required to respond to, a collection of information unless it
displays a currently valid OMB control number.
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that we do not need to prepare an environmental
assessment, as defined under the authority of the National
Environmental Policy Act of 1969, in connection with regulations
adopted under section 4(a) of the Act. We published a notice outlining
our reasons for this determination in the Federal Register on October
25, 1983 (48 FR 49244).
References Cited
A complete list of all references cited in this rule is available
on the Internet at http://www.regulations.gov or upon request from the
Field Supervisor, South Florida Ecological Services Office (see FOR
FURTHER INFORMATION CONTACT).
Author
The primary author of this emergency rule is the staff of the South
Florida Ecological Services Office (see FOR FURTHER INFORMATION
CONTACT).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as follows:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Public Law 99-625, 100 Stat. 3500; unless otherwise
noted.
0
2. Amend Sec. 17.11(h) by adding new entries for the following, in
alphabetical order under Insects, to the List of Endangered and
Threatened Wildlife:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
[[Page 49567]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
------------------------------------------------------------ population
where Critical Special
Historic range endangered Status When listed habitat rules
Common name Scientific name or
threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Insects
* * * * * * *
Butterfly, cassius blue............ Leptotes cassius U.S.A. (FL), Bahamas, NA T(S/A) ........... NA 17.47(a)
theonus. Greater Antilles,
Cayman Islands.
Butterfly, ceraunus blue........... Hemiargus ceraunus U.S.A. (FL), Bahamas. NA T(S/A) ........... NA 17.47(a)
antibubastus.
* * * * * * *
Butterfly, Miami blue.............. Cyclargus thomasi U.S.A. (FL), Bahamas. NA E ........... NA NA
bethunebakeri.
* * * * * * *
Butterfly, nickerbean blue......... Cyclargus ammon....... U.S.A. (FL), Bahamas, NA T(S/A) ........... NA 17.47(a)
Cuba.
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
0
3. In subpart D, add Sec. 17.47 to read as follows:
Sec. 17.47 Special rules--insects.
(a) Cassius blue butterfly (Leptotes cassius theonus), Ceraunus
blue butterfly (Hemiargus ceraunus antibubastus), and Nickerbean blue
butterfly (Cyclargus ammon).
(1) All provisions of Sec. 17.31 apply to these species (cassius
blue butterfly, ceraunus blue butterfly, nickerbean blue butterfly),
regardless of whether in the wild or in captivity, and also apply to
the progeny of any such butterfly.
(2) Any violation of State law will also be a violation of the Act.
(3) Incidental take, that is, take that results from, but is not
the purpose of, carrying out an otherwise lawful activity, will not
apply to the cassius blue butterfly, ceraunus blue butterfly, and
nickerbean blue butterfly.
(b) [Reserved]
Dated: July 27, 2011.
Gregory E. Siekaniec,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-19812 Filed 8-9-11; 8:45 am]
BILLING CODE 4310-55-P